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Introduction To Technical Operation & Video Editing. Objectives. Know the story you are trying to tell. Resources. From this knowledge will come your kit, crew, location, etc. What is the most important part of creating a picture?. What is the most important part of creating a picture?.

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Introduction To Technical Operation & Video Editing

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Introduction to technical operation video editing

Introduction To Technical Operation &Video Editing



Know the story you are

trying to tell



From this knowledge will come your kit, crew, location, etc.

What is the most important part of creating a picture

What is the most important part of creating a picture?

What is the most important part of creating a picture1

What is the most important part of creating a picture?

The 3 F’s

What is the most important part of creating a picture2

What is the most important part of creating a picture?

  • Focal length – to give you shape, size and content.

  • F number – aperture to give you picture quality and depth of field.

  • Focus to give you definition and selection.

What is the most important part of creating a picture3

What is the most important part of creating a picture?

  • Get these right every time and you are a long way down the road to success.

Knowledge creative power

Knowledge = CreativePower

  • You get what you pay for and this shows in the quality of the glass, and the build - through to the resolving power of the lens.

  • Always buy the best you can afford.

Knowledge creative power1

Knowledge = CreativePower

  • With semi-professional and consumer camcorders they don’t have the option of changing lenses.

Knowledge creative power2

Knowledge = CreativePower

  • Modem technology gives you automatic focus, automatic aperture, motorised zoom; all you have to do is point and press the button.

Knowledge creative power3

Knowledge = CreativePower

  • Are you in control, do you understand what is happening?

  • If not, its a pity because you will be losing out on one of the most creative skills in film making.

  • The lens is far more than a piece of glass through which a picture is taken. It is the tool you use to tell the story as you see it and, more importantly, how you want it to be seen.

The camera never lies

“The camera never lies?”

  • If that is the case you and I will be out of a job.

  • There are occasions when accurate recordings have to be made.

  • In storytelling the camera, if not exactly lying, is often economical with the truth.

The camera never lies1

“The camera never lies?”

  • It needs to be because we live in a three dimensional world and film gives two dimensional pictures.

  • Perspective, depth, the impression of a three dimensional image telling your story is all down to the use of a lens of the correct focal length placed in the right position.

Focal length

Focal length

  • Determines image size and extent of view.

  • It is the physical distance measured from the rear node of the lens (the bit at the back of the lens that bends the light rays coming in) to the point of focus (focal plane) when the lens is focused at infinity.

Focal length1

Focal length

  • This distance produces a figure in millimetres. The larger the figure the greater the distance from the rear node of the lens to the focal plane. The longer the focal length, the narrower the angle, the bigger the picture. The smaller the focal length, the shorter the distance from the rear node of the lens to focal plane, the wider the angle of view.

Focal length of single lens

Focal length of single lens

Focal length of compound lens

Focal length of compound lens

Pre focusing


  • When the production requirement is for a zoom-in to a subject, the lens must first be fully zoomed in on the subject and focused, then zoomed out to the required starting shot. The zoom will now stay in focus for the whole range of its travel. If possible, always pre-focus before zooming in.

Zoom lenses

Zoom Lenses

  • The zoom lens gives you an infinite variety of focal lengths, but there can be a price to pay.

  • The lens’ resolving power, speed (the amount of light it transmits).

  • The ability to focus on small subject-to-camera distances. Although there are various lens attachments, such as diopters.

Zoom lenses1

Zoom Lenses

  • Zoom lenses are identified by the range of variation in their focal length.

  • 6-1 would have a ratio of say

    from 9mm - 54mm

  • 10-1 say 12mm - 120mm, and so on.

  • Standard kit would include two zoom lenses like the above - these being the most practical.

Zoom lenses2

Zoom Lenses

  • A lens manufacturer will state zoom ratio and the wide-angle focal length in one figure. A ‘14 x 8.5’ zoom lens for a 2/3 inch CCD camera can therefore be decoded as a zoom with a 14:1 ratio starting at 8.5 mm focal length (angle of view = 56º) with the longest focal length of 14 x 8.5 mm = 119 mm (angle of view 4º).

  • The zoom ratio thus (approximately) equates to ‘14 x ’ i.e. 14 x 4º = 56º.

Zoom lenses3

Zoom Lenses

  • Lenses with ratios as high as 70:1 can be obtained but the exact choice of ratio and the focal length at the wide end of the zoom will depend very much on what is required from the lens.

Range extender


A zoom lens can be fitted with an internal

range-extender lens system which allows the zoom to be used on a different set of focal lengths. A 2x extender on the 14 x 8.5 zoom would transform the range from 8.5 - 119 mm to 17 - 238 mm but it may also lose 2 stops approaching maximum focal length of (238 mm).

Zoom lenses4

Zoom Lenses

  • A zoom lens, is made up of lots of glass, some of which moves and all of which absorbs and scatters light.

  • The quality and range of the modem zoom lens is second to none, reducing the need to change lenses unless for a specific need.

Prime lenses

Prime Lenses

  • Prime lenses (lenses of fixed focal length) from wide angle to tele photo.

  • Have the advantages of greater speed.

  • Allow more light to be transmitted through the body of the lens.

  • Greater resolving power.

  • Minimum subject-to-lens focussing distances improved.

Macro photography

Macro Photography

  • Ranges of special lenses that can be hired and some zooms have this facility built in.

  • The extended focusing needed to achieve a sharp image alters the light transmissions and depth of field, etc. but shouldn’t worry those working with decent viewing facilities.

  • It goes without saying a decent tripod is a must.

The speed of a lens

The ‘speed’ of a lens

  • This relates to the ability of a given lens to transmit a large amount of light.

  • Prime lenses normally have the edge over a zoom. There are also other advantages such as quality and resolution of the image, but with the onset of modern zoom lenses some of these can be argued.

The speed of a lens1

The ‘speed’ of a lens

  • Speed is important in low key or very low light conditions where you want maximum aperture and still retain quality.

  • Prime lenses often have wide diameters giving minimum F-number and yet are still compact and manageable.

  • They are in the main faster.

F number


  • The f-number of a lens is a method of indicating how much light passes through the lens. It is proportional to lens diameter and inversely proportional to focal length. For a given focal length, the larger the aperture of the lens, the smaller its f-number and the brighter the image it produces.

F number1


  • 1.4 2 2.8 4 5.6 8 11 16 22

F number2


  • Each division on this scale is called a ‘stop’. Half a division would be a ‘half stop’. The effective aperture of a zoom is not its actual diameter, but the diameter of the image of the diaphragm seen from in front of the lens. This is called the entrance pupil of the lens.

Story telling with focal length

Story-tellingwithFocal Length

  • Director use a viewfinder. Assuming he, or she, is not posing (although many do!), what they are actually doing is looking to find the right focal length lenses and subject distance to tell their story.

Story telling with focal length1

Story-tellingwithFocal Length

  • Once you have settled on a lens size and subject distance you have to be careful to follow this as any changes can alter perspective.

Story telling with focal length2

Story-tellingwithFocal Length

  • To the extremes, we have all seen the interviewee whose nose seems twice the size of her face, caused by the short focus wide angle lens on the camera being held too close to subject. Or the long focal length lens shot of the train approaching the station all crunched up when the doors open.

Story telling with focal length3

Story-tellingwithFocal Length

  • Perspective plays a significant role in story telling and is part of the director/cameraman's creative skill - but it needs to be understood.

Story telling with focal length4

Story-tellingwithFocal Length

  • This applies to documentary as much as to drama, although clearly in documentary work you may not have much time to consider such niceties.

  • Mismatching of shots, changes of subject-to-lens distances and lens sizes (and thus perspective) are all there ready to catch the unwary. People do notice.

Story telling with focal length5

Story-tellingwithFocal Length

  • It is not for nothing a major part of set design is to ensure the camera can get in the right place to give the correct perspective.

Story telling with focal length6

Story-tellingwithFocal Length

  • The type of shot created by a certain focal length is not difficult to learn, neither are its limitations and benefits.

  • Once you have this knowledge you can apply it with confidence

Angle of view


  • The approximate horizontal angle of view of a fixed focal length lens can be calculated by using its focal length and the size of the pick-up sensors of the camera.

  • For most broadcast cameras (2/3 inch CCDs) the formula would be:

    angle of view = 2 tan-1 8.8 mm (width of CD)

    2 x focal length (mm)

Calculating angle of view

Calculating angle of view



  • When zooming in, entrance pupil becomes larger until it equals diameter of focusing lens group and cannot increase in size, f-drop or ramping may cause underexposure at low light levels.

  • Increasing the diameter of the focusing lens group to avoid ramping increases the weight and the cost of the lens.



F drop of a zoom lens

Entrance pupil


  • In low light conditions (e.g. twilight evening sports events) when the lens aperture may be at its widest at the start of a zoom-in, the picture may be underexposed when the zoom reaches its longest focal length.

Entrance pupil1

Entrance Pupil

Adjusting flange back back focus

Adjusting flange-back(back focus)

1. Set the IRIS selector to Manual.

2. Place star burst lens chart at approx.

3 m or more and open aperture to maximum. Adjust for correct exposure by using either ND filters or adjusting light on the chart.

3. Zoom in on star burst chart.

4. Adjust for sharp focus on chart with front focus ring.

Adjusting flange back back focus1

Adjusting flange-back(back focus)

5. Zoom out to widest angle.

6. Loosen the flange-back (fF) adjustment ring lock screw.

7. Adjust fF for optimum definition on chart.

Do not touch zoom focus ring. (NB FLANGE-BACK position should be close to standard marked position on lens)

Adjusting flange back back focus2

Adjusting flange-back(back focus)

8. Repeat steps 4 through to 7 until focus is correct at telephoto and wide angle positions.

9. Tighten the fF adjustment ring lock screw.

Switch in RANGE EXTENDER. Zoom in and focus. Zoom out and check that zoom holds focus over complete range.

Knowledge creative power4

Knowledge = CreativePower

Camera line up colour temperature

Camera Line-upColour Temperature

  • Colour television transmission relies on an additive colour system of green, red and blue combining in different ratios to produce all the colours in the spectrum.

Camera line up colour temperature1

Camera Line-upColour Temperature

  • A combination of

    • 30% of red +

    • 59% of green +

    • 11% of blue

      will produce one unit of white and it is white that requires the greatest attention in camcorder line-up.

Camera line up colour temperature2

Camera Line-upColour Temperature

  • Colour temperature range

    A convenient way of defining the colour of a light source is to quote its colour temperature in Kelvin (K). Typical values of everyday light sources are:

Camera line up colour temperature3

Camera Line-upColour Temperature

Camera line up colour temperature4

Camera Line-upColour Temperature

  • Colour cameras are designed to operate in a tungsten environment. Processing of the output from the Red, Green and Blue sensors is normalized to signal levels produced by a scene lit with tungsten lighting (3200K). When the camera is exposed to daylight, it requires significant changes to the red channel and blue channel gains to achieve a ‘white balance’.

Camera line up colour temperature5

Camera Line-upColour Temperature

  • To ‘equalize’ the daylight to tungsten the camera is fitted with a filter wheel in front of the light-splitting block. This allows the insertion of a minus blue filter (Wratten 85B) for scenes when the camera is exposed to daylight (5600K filter position).

Camera line up colour temperature6

Camera Line-upColour Temperature

  • The filter loses approximately one stop of sensitivity. It is necessary therefore to increase the lighting level accordingly. When operating in daylight, approximately twice the scene illumination is required compared with the same scene lit by tungsten light.

Camera line up colour temperature7

Camera Line-upColour Temperature

  • Note that the 3200K filter position used for tungsten lighting is a clear glass.

  • The ‘electronic blue’ device fitted in some cameras allows daylight colour balance with no loss of light using filter position 1 - clear glass.

  • This can be useful in emergencies to gain a stop of sensitivity or in circum­stances where one has total control of the ‘daylight’ (e.g. when using HMIs in an enclosed location).

Neutral density filter

Neutral density filter

White balance

White Balance

  • Because the colour temperature of different light sources and mixture of light sources varies, it is essential to select the correct filter and white balance the camera whenever you suspect a change has occurred.

White balance1

White Balance

  • The white object must be illuminated by same lighting conditions as the one used for recording.

  • The reference white must be near centre of frame and not less than 20% of picture area. It should be evenly lit with respect to colour and shading and contain no bright highlights.

  • Select filter to match colour temperature of light illuminating white object.

Checking the white balance by recording on tape

Checking the white balance by recording on tape

  • The white balance can be checked on tape by recording a white object and then onreplay pressing CTDM button. While holding it pressed, check that CTDM picture in viewfinder matches the following diagram.

Checking the white balance by recording on tape1

Checking the white balance by recording on tape

If the white balance has been adjusted correctly, brightness will be equal over these three areas

White area

Original Picture

CTDM Picture

Using a and b white balance memory

Using A and Bwhite balance memory

  • It is sometimes possible to white balance a daylight exterior on filter 1 (3200K). If this value is memorized on memory A and a tungsten-lit interior is memorized on memory B, a development shot can start exterior on A, and on the point of transition on entering the interior, memory B can be selected and an instant white balance is accomplished.

White balance2

White Balance

  • White balancing is pointing the camera at a bit of white paper and pressing the switch/button, what could be simpler?

  • WRONG! or dangerously close to being wrong! To see why, let's consider what the camera does when you white balance.

White balance3

White Balance

  • In a broadcast 3CCD camera, the light coming from the lens is split into three colour components, red, green and blue. All colours in the visible spectrum can be synthesised through a combination of these three colours (RGB) and, from the camera's point of view, 'white' light is an equal combination of all three. So, when you perform a white balance, the camera's circuitry adjusts the output of the three CCD's to equal (maximum) voltage on the brightest portion of the image, as it assumes that this area is white.

White balance fill the whole of the screen

White Balance fill the whole of the screen.

  • Immediately, one cardinal rule to observe is, fill the whole of the screen with the white reference. Yes, I know we're told that the camera only needs the white to fill 50% (or even less!) of the frame, but if you happen to have a brighter area in the frame (eg. a mirror, or highly reflective silver, aluminium, metal, etc) you run the risk of it producing a brighter reflection than your foreground white level, which could be any colour!

White balance4

White Balance

  • Cameras may automatically adjust their iris when you press the white balance switch/button, so the camera exposes for the brightest area in frame before white balancing on it.

  • Readjust the iris to the correct exposure before recording.

Fill the frame

Fill The Frame

  • Fill the frame and expose the picture so that the card registers close to peak white (the onset of zebra patterning, depending on the threshold of the zebra setting). Care: do not overexpose. If in doubt, back off to the onset of the zebra. If the camera is overexposed, the signals from the CCD’s are going into the clipper, and this could all too easily produce an incorrect white balance. (If in doubt, set the lens iris to auto exposure whilst you perform the white balance. This should obviate the problem:)

Reference white

Reference White

  • Just as important, you must select your reference 'white' with care, not just any old notebook, tissue, newspaper that's handy. I suggest you carry a piece of (non-glossy surfaced) matt white card (as opposed to paper, which is too easily crumpled, marked, torn, blown at different angles in the wind, etc.) which has no colour cast, since ideally, you should use the same piece of reference white throughout a shoot. (Light grey is also OK, as long as you're certain it's a neutral grey.)



  • Care must be taken in positioning the white card. Make sure it is held such that the 'white' source of light to which you want to balance is the only illumination falling on it. For example, if you are in town at night, and there are flashing neon lights, moving car headlights, illuminated shop windows, traffic lights, zebra crossings, etc you may need to move from the shot position to do a white balance, in order to ensure that your main source of illumination ('white' light) is the only one falling on your white card.

Held stable

Held Stable

  • Ensure the card is held stable, and that its angle to the light source doesn't alter whilst white balancing. Instil into your long-suffering assistant, sound recordist, PA, director, producer that it mustn't move at all until you're satisfied with the balance.

Held stable1

Held Stable

  • If the card is accidentally moved whilst the camera is white balancing you may pick up a stray reflection of unwanted light. Since the card should fill frame, whilst you're looking in the viewfinder to check the colour temperature readout, you may not notice an unintentional change in angle of card position.

Held stable2

Held Stable

  • Ensure the card is held stable, and that its angle to the light source doesn't alter whilst white balancing. Instil into your long-suffering assistant, sound recordist, PA, director, producer that it mustn't move at all until you're satisfied with the balance.

Daylight and tungsten

Daylight and Tungsten

  • Daylight is much bluer than tungsten light; or looked at the other way round, tungsten is orange compared to daylight. The human eye/brain automatically compensates for the colour of light falling on a scene, and we see the 'correct' colour. Unfortunately, cameras do not have this automatic ability (or not reliably, as yet!) So we have to show them what we want them to read as 'white' in any given scene.

Daylight and tungsten1

Daylight and Tungsten

  • Both daylight and tungsten light sources have continuous spectra, in other words, light from either source passing through a prism produces a 'rainbow' spectrum, a blend of all colours from darkest red through to deepest violet, with no discernible gaps between individual colours. This is the 'type' of light that the camera expects to see, a continuous spectrum, when it performs a white balance.

Colour temperature

Colour Temperature

  • The 'colour' of light is quoted as a colour temperature in degrees Absolute, called Kelvin, which are the same 'size' degrees as Celsius, but starting at absolute zero (-273° C) as 0° K, thus making 0° C = 273° K, and 100° C = 373° K. The figure for the colour temperature of a specific source of light is derived from the equivalent temperature of a black body radiator producing an identical colour.

Wrong colour

Wrong Colour!

  • Unless the camera registers 'white' correctly, then people will certainly appear the wrong colour! And it's people who are the main subjects on television over 90% of the time. If they don't look right, viewers will spot your mistake straight away. Care must always be taken to avoid any green or blue cast on white skin.

Sequence of shots

Sequence of Shots

  • No shot stands alone, and in any given location, and within a sequence of shots, or scene, you must endeavour to maintain consistency with your white balance. In an ideal world, you would white balance before shooting a scene, and stay with that setting until the end. Unfortunately, on location, life rarely treats us that well, and knowing how often to white balance is mostly a matter of experience.

No change in your lighting

No change in your lighting

  • As long as there is no change in your lighting set-up, which is probably another way of saying, as long as you aren't dependent on daylight illumination for any picture area, then you should only need to white balance once before shooting.

No change in your lighting1

No change in your lighting

  • Then, assuming you are working with light sources with continuous spectra, the only correction that may need to be applied during post production will be a small amount of plus or minus blue in order to correctly colour match shots (to allow for any fluctuations in mains voltage and fading gels throughout the shoot).

Daylight uncontrollable

Daylight Uncontrollable

  • Daylight illumination is totally natural, often looks great, but it's uncontrollable. A day of sunshine and showers may well drive you round the bend with changes in both level of illumination and colour temperature. Even though you white balance with every change in the weather, you must warn production that they may almost certainly have to perform some colour correction during post production.

White balance confusion

White Balance Confusion

  • This is where confusion arises over what white balance can and cannot do. Let's imagine that you're on location indoors, and you start shooting a scene in the morning, lit by daylight - 5,600K (and/or augmented with tungsten lights which have full CTB gels), and perform a white balance on position A.

White balance confusion1

White Balance Confusion

  • Subsequently, white balance on the same scene during the evening, on position B, because the colour 'values' of objects within the scene will not be the same, although white (and shades of grey) will be 'colour' correct, ie. neutral.

White balance confusion2

White Balance Confusion

  • This difference in perceived colour 'values' is fundamental to the 'phenomenon' of colour itself. Objects derive their colour (as perceived by the eye/brain) from the wavelengths of light they reflect, so illuminating said objects with light differing colour temperatures automatically alters their appearance to the eye (and the camera), in relationship to each other. Viewing objects in everyday life (and therefore in 'real' time), we are unaware of these differences, due to the eye/brain 'automatic' compensation.

White balance confusion3

White Balance Confusion

  • So, should the shooting of a particular scene be extended after daylight has disappeared?

  • You must continue to work under light at the original colour temperature of 5,600K (or whatever your original white balance reference displayed) to ensure continuity of colour values.

Continuity of colour values

Continuity ofColour Values

  • Changing lens can affect colour relationships. The types of glass used in lenses vary between make and model, and even if you stick to one manufacturers lens range, the age and state of the lens also affects light transmission. Thus, a small amount of colour correction may need to be applied in post production for such a minor event as a lens change!

Continuity of colour values1

Continuity ofColour Values

  • If you're using more than one camera, irrespective of make and model lens combination, white balancing alone is unlikely to result in pictures that are fully colour matched. Even white balancing simultaneously on the same white reference cannot guarantee pictures having the same colour values.

Continuity of colour values2

Continuity ofColour Values

  • There are too many variable such as lens, internal (and external, if in use) filters, chip block, and camera line-up.

  • You will be unable to cut or edit between shots from separate cameras without some difference in colour being perceptible.

Continuity of colour values3

Continuity ofColour Values

  • Lining up the cameras side by side can alleviate most of these problems but for critical applications the only way to completely colour match several cameras is by using a vision operator, or in post production.

Location and operation

Location and Operation

  • The location and operation of each switch/button for white balancing on the different makes/models of camera you're likely to use can be different.

Location and operation1

Location and Operation

  • On Sony cameras, you press the switch up and let go, but on Ikegami cameras, you press a button and hold it in until the viewfinder display confirms that the camera has white balanced. So, before you use any piece of equipment for the first time, do ensure you've located the relevant controls, and confirmed how they operate.

White balance the rules

White BalanceThe Rules!

  • On the camera's filter wheel, select the filter number providing the closest match to the colour temperature of your main light source.

  • Select A or B on camera switch, to store the white balance.

  • Use a matt white card, and keep it protected/clean (carry a matching spare).

White balance the rules1

White BalanceThe Rules!

  • Hold it stable, and positioned/angled so that it is illuminated by your chosen 'white' light.

  • Zoom in to the white card to fill the frame.

  • Expose the card to peak white/onset of zebra (care: do not overexpose).

  • Press the white balance switch/button.

  • Read the colour temperature displayed in the viewfinder, check – is it sensible?

White balance notes

White BalanceNotes

  • Left and right, when referring to cameras, is determined by the cameraman's operating position, and is thus the same as camera left and camera right.

White balance notes1

White BalanceNotes

  • The 'colour' of any object seen by the eye is produced by the wavelengths of light that, that object reflects. Thus some wavelengths are absorbed and some reflected. 'White' light comprises a complete spectrum of colours, and the combination of the reflected wavelengths produces the perceived 'colour' or shade of the object.

White balance notes2

White BalanceNotes

  • CTB: Colour Temperature Blue, accurate conversion filters which are available in a wide range for colour correction, the most common ones in use being full, half, quarter and eighth blue gels.

  • CTO: Colour Temperature Orange, with an equivalent range .

White balance notes3

White BalanceNotes

  • The consistency of gels is problematic, as they discolour through use due to high lamp temperatures. This alters/distorts their colour temperature shifting properties.

  • Keep a good stock of new gel, and replace as often as necessary.

White black balance notes

White Black BalanceNotes

  • The Sony BVW300/400, if you push this switch down, you perform a black balance. The camera automatically caps up (the iris stops down), and checks the 'black' level of each of the R G & B channels, and adjusts the output if necessary to ensure they're equal, ie. zero.

Black balance

Black Balance

  • Black balance is normally only required if the camera has not been in use for some time or if the camera has been moved between radically different temperatures. First adjust the white balance to equalize the gains and then black balance (then white balance again).

Contrast range

Contrast Range

  • Variation of brightness is the contrast range of the scene.

  • The relationship between the brightest part of the subject and the darkest part is the contrast ratio. The average exterior contrast ratio is approximately 150 :1 but it can be as high as 1000:1.

Contrast range1

Contrast Range

  • Achieving the correct exposure for any specific shot therefore requires reproducing the detail in the highlights as well as in the shadows of the scene.

  • Skin tones need to be set between 70% and 75% of peak white

Contrast range2

Contrast Range

  • Sounds deceptively simple, especially when there is a specific control on the camera to do the job for you (auto-iris), but like many other descriptions of television technique, a simple statement can gloss over a multitude of practical problems.

Video contrast range

Video Contrast Range

  • The contrast ratios of everyday location and interiors can range from 20:1 to 1000:1, a video camera can only record a scene range of approximately 40:1

  • The result of recording a contrast range greater than the camera can handle is that highlights of the scene will appear a uniform white - details in them will be burnt out and the darker tones of the scene will be a uniform black.

Video contrast range1

Video Contrast Range

  • The limiting factor for highlight detail in high-contrast scenes is the peak white clipper circuits and the ‘knee’ of signal amplification in the camera.

Video contrast range peak white clippers

Video Contrast RangePeak White Clippers

  • There are three peak white clippers, one in each colour channel, and their function is to limit any part of the scene that would produce a signal greater than a pre-set value. Their effect is to render all gradations in brightness above the ‘clip’ level as white - to burn out any overexposed parts of the picture.

Video contrast range knee

Video Contrast RangeKnee

  • The ‘knee’, which is introduced into the camera head amplifiers, progressively compresses highlights which otherwise would be lost in the peak white clipper. It extends the camera’s response to a high contrast range but with some loss of linearity.

Camera response without knee

Camera Response Without ‘Knee’

Clip level







0.45 gamma

Log light in

Recorded contrast range

Original contrast range

Camera response with knee

Camera ResponseWith ‘Knee’

Clip level







0.45 gamma

Log light in

Recorded contrast range

Original contrast range

Dynamic contrast control

Dynamic Contrast Control

  • Another way of accommodating a high-contrast scene is to alter the camera’s transfer characteristics by using the DCC circuit. This compresses highlights to allow a greater contrast range than normal.

Peak white and black

Peak white and black

  • A camera’s contrast range is determined by the noise level which limits the darkest area of the scene which can be reproduced and the video peak level of maximum signal which clips the highlight detail.

  • When a high contrast scene such as an exterior in bright sunlight is recorded, most of the detail in the highlights will be reproduced as solid white.

Peak white and black1

Peak white and black

  • If a highlight compression circuit is used (DCC), the highlight part of the signal is non-linear amplified. As the magnitude and the size of the highlight areas increase, a ‘knee’ circuit compresses the highlight to keep it within the normal peak video level. Increasing the highlight will reduce the knee threshold still further.

Exposing for highlights

Exposing for highlights

  • A highlight part of the shot may produce a signal 5 times peak white level can be compressed into the normal video dynamic range. This means that the darker areas of the picture can be correctly exposed while at the same time maintaining some detail in the highlight.

Exposing for highlights1

Exposing for highlights

  • If someone was standing in a room against a window and it was necessary to expose for exterior detail and the face, without additional lighting or filtering the windows, it would not be possible to reproduce detail in both face and exterior. Using highlight compression, the highlights outside the window would be squashed by the DCC circuit and although their relative brightness to each other would not be faithfully reproduced, the compression would allow the reproduction of detail across a greater range to be recorded.

Transient highlights

Transient highlights

  • If DCC is used with a normal contrast range scene (below 40:1), there is the risk that highlights will be distorted and the compression may result in a lower contrast reproduction than the original.

Factors limiting contrast range

Factors limitingcontrast range

White clip

Normal camera dynamic range

Noise floor

Black detail

Factors limiting contrast range1

Factors limitingcontrast range

  • The contrast range of a camera is limited by noise level in darkest area of picture and maximum signal is fixed by the 700mV video peak level of the PAL system. Any detail above white clip level will be reproduced as white.

Variable slope highlight control

Variable slopehighlight control


Extra compression

Slope varied in proportion to amount of highlight details that would be clipped

Log Vout

Knee point fixed

-2 -1 0 +1+2

Stops overexposed

Variable knee point highlight control

Variable knee pointhighlight control


Log Vout

Angle of slope fixed

Knee point moved to keep highlights below clip level

-2 -1 0 +1+2

Stops overexposed

The interview talking head

The Interview‘talking head’

  • Video pictures of faces are the most demanding in achieving correct exposure and usually require exposure levels that are high but are free from burn-out in highlight areas.

The interview exposure continuity

The InterviewExposure continuity

  • An important consideration when shooting the same face in different locations or lighting situations is to achieve some measure of continuity in face tones.

Relationship between face tones and reflectance

Relationship between face tones and reflectance

*Zebra setting on 300 camera as delivered — 68% of peak white.

Zebra exposure indicator

Zebra Exposure Indicator

  • The zebra pattern is a visual indicator in the viewfinder when areas of the picture have reached a certain signal level. If the zebra exposure indicator is switched on, those elements of the image that are above this pre-set level are replaced by diagonal stripes in the picture. The cameraman can respond by closing the iris to adjust the exposure until part or all of the zebra diagonals have been removed.

Selecting zebra level

Selecting zebra level

  • The exposure point at which the zebra indicator is triggered can be a personal operational preference, but criteria to consider when setting that point are:

Selecting zebra level1

Selecting zebra level

1.If there is a ‘pool’ of cameras in use, then that point should be standard on all cameras.

2.The onset point should be close to full exposure but should warn before full burn-out occurs.

3.The zebra strip indicator should not obscure important picture information such as the face, but it should indicate when flesh tones are in danger of going over into overexposure.

Selecting zebra level2

Selecting zebra level

  • Some UK zebra onset levels are 90 - 95% for RGB-driven systems and 68% for luminance systems, but the final limiting factor on exposure level is loss of detail, either to noise in the blacks or burn-out in the peak white clipper. Both losses are irrecoverable.

Audio recording tracks

Tape upper edge

Audio 2

Audio 1

Direction of head travel

Y Track

C Track

Direction of tape travel


Time Code

Reference edge

Audio Recording Tracks

AFM sound recorded in ‘C’ track

Betacam sound

Betacam Sound

  • Audio recording tracks on BetacamBetacam SP has the facility of recording four audio tracks. Two of these tracks (Channel 1 and Channel 2) are recorded on the longitudinal tracks and Channel 3 and Channel 4 are recorded on the AFM tracks encoded into the vision area of the tape.

Betacam sound1

Betacam Sound

  • Four separate audio inputs can be recorded on the BW-5PS VT recorder. If only the two longitudinal tracks are used (Channel 1 and Channel 2), the inputs can be switched to duplicate the audio recordings onto the FM tracks (Channel 3 and Channel 4).

Betacam sound2

Betacam Sound

  • The BVP300 and BVP400 series camcorders have a maximum of two separate audio inputs that are recorded on Channel 1 and Channel 2.

  • These tracks can be duplicated on Channel 3 and Channel 4.

  • No separate audio input can be plugged direct to the FM Channels 3 and 4.

Betacam sound3

Betacam Sound

  • In ‘one-man’ operation, always use Channel 1 as there are two gain controls, one of which can be monitored and controlled through the viewfinder.

Betacam sound mic front

Betacam SoundMic Front

  • When an audio channel is switched to this position, any microphone connected to the front audio input (e.g. camera-mounted) will be selected.

Betacam sound mic rear

Betacam SoundMic Rear

  • This position enables the user to plug a microphone into the connector at the rear of the camera. On some Beta format cameras, a separate switch can be found under the Mic input marked +48 volts (Phantom Power) that supplies power to the microphone if required.

Betacam sound line

Betacam SoundLine

  • When an audio channel is switched to this position, an external audio mixer can be connected. All microphones to be used are connected and controlled via this mixer and its input sensitivity to the Betacam is (0dB), that is known as Line Level. Line input can also be used for a feed from a public address system mixer before amplification.

Audio levels sound intensity range

Audio LevelsSound intensity range

  • The intensity of sound is a function of the pressure variation set up in the atmosphere. Intensity is proportional to pressure squared. A microphone is used to convert sound energy into electrical energy and the voltage produced is proportional to the sound pressure.

Audio levels sound intensity range1

Audio LevelsSound intensity range

  • The range of intensities from quietest to loudest is the dynamic range of that sound situation. For example, the ratio of the loudest sound produced by an orchestra to the quietest sound can be as much as 60 - 70dB in an orchestral performance. This dynamic range is greater than can be transmitted and therefore sound control and possibly sound compression is required when recording large variations in sound levels.

Audio levels decibels

Audio LevelsDecibels

  • Our ears do not respond to changes in sound intensity in even, linear increments. To hear an equal change in intensity, the sound level must double at each increase rather than changing in equal steps. To match the ear’s response to changes in sound intensity, it is convenient to measure the changes in the amplitude of the audio signal by using a logarithmic ratio - decibels (dB). Decibels are a ratio of change and are scaled to imitate the ear’s response to changing sound intensity.

Audio levels decibels1

Audio LevelsDecibels

  • If a sound intensity doubles in volume, then there would be a 3dB increase in audio level. If it was quadrupled, there would a 6dB increase.

Audio levels zero level voltage

Audio LevelsZero level voltage

  • Just as light is converted into a TV signal with a standard peak amplitude of O.7V, so sound energy when it is converted into electrical energy requires a standard signal, a baseline voltage to which all changes can be referred. This is known as zero level and the standard voltage selected is 0.775V — the voltage across 600ohms (a common input and output impedance of audio equipment) when 1mW is developed.

Audio levels zero level voltage1

Audio LevelsZero level voltage

  • 1000Hz is the frequency of the standard zero level signal. Increasing or decreasing sound intensity will alter the level of this voltage.

Audio levels sound monitoring

Audio LevelsSound monitoring

  • Two types of meter are used to measure and monitor changes in audio level. A peak programme meter (PPM) measures peaks of sound intensity. A programme volume meter (VU) measures average level of sound and gives a better indication of loudness but at the expense of missing brief high-intensity peaks that could cause distortion. When relying on a VU meter, always ensure that the needle only occasionally goes into the red zone on the meter display. Try to maintain a signal at - 2dB.

Audio levels microphone sensitivity

Audio LevelsMicrophone sensitivity

  • The sensitivity or output of a microphone is expressed in units of millivolt / pascal (mV/Pa) but more commonly quoted in comparison to 0dB line level in decibels (dB). The more negative the dB figure, the less sensitive the microphone.

Audio levels microphone sensitivity1

Audio LevelsMicrophone sensitivity

  • For example, the output of a hand-held moving coil microphone will be in the region of -75dB and is less sensitive than the output of a short condenser microphone which will be around -55dB.

  • Usually the camera microphone input sensitivity is around -70dB; therefore most types of microphone can be used directly into the camera.

Audio levels power supplies to microphones

Audio LevelsPower supplies to microphones

  • Before plugging a microphone into an audio input, check the position of the phantom power switch. Switch the supply to ON only if the condenser microphone requires a 48V supply. For an ‘in line’ condenser microphone (one fitted with a battery), check the condition and charge of the batteries in the microphone.

Audio levels sound monitoring through the viewfinder

Audio LevelsSound monitoring through the viewfinder

  • If you are using a single microphone into the camera, always use TRACKONE:

    1.Having connected the mic and selected mic position, turn the gain control at the side panel of the camera to maximum.

Audio levels sound monitoring through the viewfinder1

Audio LevelsSound monitoring through the viewfinder

2.Select the viewfinder for metering of audio. Obtain a sound level and adjust the front gain control on the viewfinder to bring down the level to three dashes on the viewfinder audio level indicator (equivalent to 0dB). Reduce rear audio gain on side panel if sufficient attenuation cannot be achieved.

3.You now have attenuation and gain should it be required on the front audio control.

Audio levels audible sound checks

Audio LevelsAudible sound checks

  • Sound quality can be checked by headphone or speaker:-

Audio levels audible sound checks1

Audio LevelsAudible sound checks

  • PB - To monitor playback sound during recording which will supply a mix of Channels 1 and 2. There is often the interference of time code spill and therefore the audio monitoring on PB provides a confidence check (i.e. sound has been recorded - ‘an echo’) and not a quality check.

  • EE - Amplified audio signal can be checked before it is recorded.

Audio levels problems

Audio LevelsProblems

  • If a microphone is connected to the camera mic input with the correct power supply, but the level control has to be placed at maximum to obtain the slightest movement of the meter (i.e. indicating low sound level or faulty mic), the end result will be a high level of unwanted noise from both the microphone amplifier along with line buzz transmitted from the viewfinder.

Audio levels problems1

Audio LevelsProblems

  • If the output of an external sound mixer were to be wrongly connected to the mic input (instead of to line), the result will be that the input gain control will be set at its minimum, and maximum deflection of the meters will show. Any audio recorded will be overload distorted and will certainly cause cross-modulation distortion on the second audio track.

Audio recording on video tape

Audio recording on video tape

Range of sounds

Range of Sounds

Range of sounds1

Range of Sounds

  • The limited dynamic range of audio recording can be shifted up or down the spectrum of human hearing to record required segment of sound intensities.

Ppm meter

PPM Meter

  • PPM registers peaks of audio level

  • Each increment on a PPM = 4dB

  • Zero level = 4

Time code tracks betacam tape

Audio 2

Audio 1

Direction of head travel

Y Track

C Track

Direction of tape travel


Time Code

Time Code Tracks Betacam Tape

Longitudinal time code is recorded on the time code track. Unless the tape is moving it cannot be decoded and displayed

Time code

Time Code






Time code1

Time Code

  • Time code enables every recorded frame of video to be numbered. This allows precise identification when editing. There are two methods of recording the identification number.

Time code longitudinal time code

Time CodeLongitudinal time code

  • Longitudinal time code (LTC) is recorded with a fixed head on a track reserved for time code. It can be decoded at normal playback speed and at fast forward or rewind, but it cannot be read unless the tape is moving as there is no replayed signal to be decoded.

  • It is recorded once every frame as a series of pulses (binary digits) whose repetition rate changes according to whether it is recording 0’s or l’s.

Time code vertical interval time code

Time CodeVertical interval time code

  • Vertical interval time code (VITC) numbers are time-compressed to fit the duration of one TV line and recorded as a pseudo video signal on one of the unused lines between frames. It is recorded as a variation in signal amplitude once per frame as binary digits. 0 equals black and 1 equals peak white.

Time code vertical interval time code1

Time CodeVertical interval time code

  • The Beta format cameras have the ability to insert VITC twice on two non-consecutive lines. They are factory-set to insert the VITC signal between lines 19 and 21 for PAL but there is provision for another choice of line position for VITC insertion independent of the first choice.

Time code code word

Time CodeCode word

  • Every frame contains an 80-bit code word which contains ‘time bits’ (eight decimal numbers) recording hours, minutes, seconds, frames and other digital synchronizing information. All this is updated every frame but there is room for additional ‘user bit’ information.

Time code user bit

Time CodeUser bit

  • User bit allows up to nine numbers and an A to F code to be programmed into the code word which is recorded every frame. Unlike the time bits, the user bits remain unchanged until re-programmed. They can be used to identify production, cameraman, etc.

Time code2

Time Code

  • There are two ways of starting time code:-

  • Record run

  • Free run.

Time code record run

Time CodeRecord Run

  • Record run only records a frame identification when the camera is recording. The time code is set to zero at the start of the day’s operation and a continuous record is produced on each tape covering all takes. It is customary practice to record the tape number in place of the hour section on the time code. For example, the first cassette of the day would start, and the second cassette would start

Time code record run1

Time CodeRecord Run

  • Record run is the preferred method of recording time code on most productions.

Time code free run

Time CodeFree Run

  • In free run, the time code is set to the actual time of day and when synchronized is set to run continuously. Whether the camera is recording or not, the internal clock will continue to operate. When the camera is recording, the actual time of day will be recorded on each frame.

Time code free run1

Time CodeFree Run

  • This mode of operation is useful in editing when covering day-long events such as conferences or sport. Any significant action can be logged by time as it occurs and can subsequently be quickly found by reference to the time of day code on the recording.

Time code free run2

Time CodeFree Run

  • In Free Run (Time of Day) - a change in shot will produce a gap in time code proportional to the amount of time that elapsed between actual recordings:

Time code free run3

Time CodeFree Run

Time code problems

Time CodeProblems

  • Missing time code numbers can cause problems with edit controller when it rolls back from intended edit point and is unable to find time code number it expects there (i.e. the time code of the frame to cut on, minus the pre-roll time).

The lighting director

The Lighting Director

  • The Lighting Director is at the hub of a lot of peoples’ efforts - the Director, the Set Designer, Make-up artist, Costume Designer, Sound Supervisor, engineers so the Lighting Director must get on with people and be able to compromise. So, personality is important as is the latent ability to do the job.

Colour temperature1

Colour Temperature

  • The intensity of a light source is defined in Foot Candles or Lux and the colour of a light source is defined in degrees Kelvin. The Kelvin scale is based on the light output of an incandescent source. Incandescent light is produced by heating an object to the point that visible light is produced.

Colour temperature2

Colour Temperature

  • When a metal (eg: tungsten) is heated it will emit visible light when sufficient heat is applied to it.

  • If we were to apply heat to the tungsten, increasing the degree of heat incrementally, we could chart the relationship between the heat applied and the colour of light emitted by the tungsten.

Colour temperature3

Colour Temperature

  • The Kelvin scale defines, in degrees Kelvin, the colour of a light's output with relationship to the degree of heat applied to produce the specified colour of light.

Colour temperature4

Colour Temperature

  • A tungsten filament light bulb placed on a dimmer illustrates this relationship. As the electrical current is increased, more resistance is created within the filament. This increases the heat of the filament. Decreasing the electrical current lowers the resistance, thus reducing the heat in the filament. When the heat of the filament is low, an amber glow is produced. The filament produces light that is less amber when the heat is increased.

Colour temperature5

Colour Temperature

  • The intensity of a light source does not influence the Kelvin temperature. The Kelvin scale measures the quality of light output and not the quantity of the light output. A light source operating at 3200 degrees Kelvin is often used as a reference "white light" source when balancing video cameras in a studio. Tungsten will melt when it reaches 3500 degrees Kelvin.

Colour temperature6

Colour Temperature

  • Light that is produced from sources other than incandescent sources (eg: arc sources) are given an approximate Kelvin value. The approximate Kelvin value given to an arc source does not represent the spikes that occur within its spectral distribution.

Colour temperature7

Colour Temperature

  • When light sources of varying Kelvin temperatures are mixed, they must be adjusted to the reference "white light" source the camera used during set-up.

  • A camera balanced for 3200 degrees Kelvin will reproduce light from a 5600 degree light source with a blue tint.

  • When 5600 degrees Kelvin is used as a line up reference then a 3200 degree source will appear with an amber tint.

Colour temperature8

Colour Temperature

  • Colour correction gel is used to alter the Kelvin output of the different light source. CTO (colour temperature orange) gel is used to alter a lights 5600 degree Kelvin output to match a 3200 degree Kelvin light source.

  • CTB (colour temperature blue) is used to alter a 3200 degree Kelvin light source to match the light output of a 5600 degree Kelvin light source.

Colour temperature9

Colour Temperature

Colour temperature10

Colour Temperature

  • NOTE: Sunlight is the light of the sun only. Daylight is a combination of sunlight plus skylight. The values given are approximate because many factors affect colour temperature.

  • OUTDOORS: the sun angle, and the conditions of the sky-clouds, haze, dust particles-raise or lower the colour temperature

Colour temperature11

Colour Temperature

  • INDOORS: lamp age (and blackening), voltage, type of reflectors and diffusers affect tungsten bulbs all of these can influence the actual colour temperature of the light.

Colour temperature12

Colour Temperature

  • Usually a change of 1 volt equals 10 degrees Kelvin. But this is true only within a limited voltage range and does not always apply to "booster voltage" operation, since certain bulbs will not exceed a certain colour temperature regardless of the increase in voltage.

Approximate correlated colour temperature for various light sources

Approximate Correlated Colour Temperaturefor Various Light Sources

Approximate correlated colour temperature for various light sources1

Approximate Correlated Colour Temperaturefor Various Light Sources

Approximate correlated colour temperature for various light sources2

Approximate Correlated Colour Temperaturefor Various Light Sources

Approximate correlated colour temperature for various light sources3

Approximate Correlated Colour Temperaturefor Various Light Sources

Filters gel

Filters (Gel)

  • Coloured filters are used in lighting to alter the output of a light source. A "white light" source is comprised of a range of colours within the visible spectrum combining to create the white light.

Filters gel1

Filters (Gel)

  • The use of colour filtration dates back to early theatres where coloured "gel" (dyed gelatine) was used to colour the lights. The term "gel" is still in use, although today's most commonly used coloured filters are plastic, polyester or polycarbonate. Polycarbonate filters tend to last longer than polyester based filters. Glass filters are also used to colour light.

Filters gel how it works

Filters (Gel)How it works

  • A colour filter blocks unwanted colour from the original light source and allows the desired colour to pass through it. As fig.1 shows the spectral colours that create "white light" are stopped by the green "gel" and only the specific green range of the spectrum are allowed to pass.

Filters gel how it works1

Filters (Gel)How it works

  • A filter cannot add portions of the spectrum that do not inherently exist within the specific light source itself.

Filters gel absorption and interference filters

Filters (Gel)Absorption and Interference Filters

  • Filters use two different methods of blocking the unwanted portions of the spectrum. Plastic based filters absorb the unwanted portions of the spectrum. This means that the infra-red (heat produced from a tungsten bulb) will be absorbed and cause the plastic to fade and deteriorate.

Filters gel absorption and interference filters1

Filters (Gel)Absorption and Interference Filters

  • Colours that block a large portion of the infra-red will deteriorate quicker than a filter that allows it to pass. A deep blue filter will deteriorate quicker than a light red filter when used in a tungsten light source.

Filters gel absorption and interference filters2

Filters (Gel)Absorption and Interference Filters

  • The second method is known as interference. Dichroic filters, also known as dichroic mirrors, reflect the unwanted portions of the spectrum instead of absorbing them. This type of filter only interferes with the original light and then allows the desired colour to pass through it.

Filters gel absorption and interference filters3

Filters (Gel)Absorption and Interference Filters

  • Dichroic filters last longer because they do not absorb the infra-red and use glass as their base. They can be shattered, like glass, so care must be taken in the handling of this type of filter. Dichroic reflectors are used in some of today's lights to allow infra red to pass out the back of the reflector while the remaining light waves are reflected into the front of the lighting instrument.

Filters gel colour correction

Filters (Gel)Colour Correction

  • When mixing two or more different light sources (eg: tungsten and daylight) a main source must be determined as your reference white light source. The camera uses this reference white to mix the portions of red, green and blue to reproduce white correctly. If the video camera uses a tungsten source, when balancing, all other light sources used in the scene should match the spectral distribution of the tungsten source.

Filters gel colour correction1

Filters (Gel)Colour Correction

  • Daylight shining in a window will appear blue when seen by a video camera adjusted for tungsten light. If you reduce the blue portion of daylight's spectral distribution and allow the red portions to be dominate, then the daylight will be closer to the tungsten light source in colour.

Filters gel colour correction2

Filters (Gel)Colour Correction

  • The filter range, designed to modify light sources so they will have a similar colour output, are termed colour correction filters. The two most common colour correction filters are grouped as:-

  • C.T.O. (colour temperature orange, to alter daylight 5600 degrees Kelvin, to tungsten).

Filters gel colour correction3

Filters (Gel) Colour Correction

  • C.T.B. (colour temperature blue, to alter tungsten 3200 degrees Kelvin, to daylight). The range of colour correction filters is wider than these two groups but they are the two most commonly used type of colour correction.

Filters gel neutral density

Filters (Gel)Neutral Density

  • Neutral Density, also known as ND, only reduces the quantity of light that passes through it. ND does not alter the original spectral colours of the light source. Daylight passing through ND will still be blue when viewed by a camera set for tungsten, only the total Foot Candle level will be reduced.

Filters gel neutral density1

Filters (Gel)Neutral Density

  • Colour correction C.T.O. is combined with ND to create a single gel that will convert 5600 degree Kelvin Daylight to 3200 degree Kelvin tungsten, while reducing the total Foot Candle level. This is commonly used on a bright daylight window when lighting inside with tungsten



  • Optical filters may be solid, liquid, or gaseous. These consist mainly of colorants dissolved in a gelatin or in cellulose acetate. Each filter, gelatin or acetate, is standardized for spectral transmittance and total transmittance by special instruments which apply an optical form of limit gauge to these characteristics.

Filter factors

Filter factors

  • Published filter factors apply strictly to the particular lighting conditions used in the laboratory where the factors were determined. For scientific applications, especially, the quality of light can vary widely so that it may be desirable to determine the filter factor for actual working conditions.

Filter factors1

Filter factors

Filter factors2

Filter factors

  • Each time a filter factor is doubled, the exposure needs to be increased by 1 stop. As an example, a filter factor of 2 requires a 1 stop exposure increase. A filter factor of 4 requires a 2 stop exposure increase.

  • Use this example for filter factors not listed in the table

Light balancing filters

Light Balancing Filters

  • Light-balancing filters make minor adjustments in the colour quality of illumination to obtain cooler (bluer) or warmer (yellower) colour rendering

Light balancing filters1

Light Balancing Filters

  • One of the principle uses for Light Balancing Filters is where light sources frequently exhibit colour temperatures different than that for which a colour film is balanced. When using a colour temperature meter to determine the colour temperature of prevailing light, you can use the table below, which converts the prevailing temperature to either 3200 K or 3400 K.

Light balancing filters2

Light Balancing Filters

Light balancing filters3

Light Balancing Filters

  • These values are approximate. For critical work, check by

  • accurate tests, especially if you use more than one filter.

Colour compensating filters

Colour Compensating Filters

  • Colour compensating filters control light by attenuating principally the red, green, or blue part of the spectrum. While controlling one colour, the filter transmits one or both of the other two colours.

Colour compensating filters1

Colour Compensating Filters

  • Colour compensating filters can make changes to the colour balance of pictures recorded on colour films, or compensate for deficiencies in the spectral quality of a light source.

Colour compensating filters2

Colour Compensating Filters

  • For optimum results, use the single recommended colour compensating filter rather than combining filters (for example, CC20Y + CC20M = 20R, so using 20R only is preferable).

Colour compensating filters3

Colour Compensating Filters

  • Gelatin Filters/Colour Compensating Filters have excellent optical quality and are suitable for image forming optical systems over-the-camera lens, for example.

Colour compensating filters4

Colour Compensating Filters

  • Dividing the normal exposure index (EI) of the film by the filter factor will give you the effective EI for the film with that filter on the lens.

  • Example: normal EI 100 FF 2 (one t-stop) = EI 50.



  • “Lighting is the art of establishing a sense of place and time and that it provides a tool for amplifying moods and emotional content of stories."



  • Trust your eyes, instincts and experience rather than trying to judge the aesthetic quality of images displayed on videotape monitors when shooting film.



  • Try to become more confident and proficient lighting by eye, rather than constantly looking through the finder and walking around the set with a spot meter glued to your face.



  • "It's important to observe how the lighting director thinks and communicates with others on the creative team to amplify story telling by adding and subtracting light, textures and colours."



  • The luminance levels of colours record differently on film than they look to the human eye, even a subtle difference in the shade of a wall behind a character can affect skin tones.

Lighting with steadicams


  • Lighting can be tricky shooting with constantly moving Steadicams.

  • Soft light overall then keep the angle low and use handheld lights traveling with the cameras for subtle fill light on close-ups.

Foot candle definition

Foot CandleDefinition

  • A "FOOT CANDLE" is a standard unit, established as reference, that is used when measuring quantity of light. As lighting professionals we need to know "how much" light we are working with. Like an inch on a ruler, a reference unit to measure physical objects, the foot candle is a reference unit for a non-physical element, light.

Foot candle definition1

Foot CandleDefinition

  • One Foot Candle equals the total intensity of light that falls upon a one square foot surface that is placed 1 foot away from a point source of light that equals 1 candle power.

  • Note: The term candela also refers to candle power, 1 candela = 1 candle power.

Foot candle definition2

Foot CandleDefinition

  • This illustrates the one square foot surface area, of illumination, that is created by a light source that equals 1 candle power at a 1 foot distance. The total illumination that falls on this one square foot surface equals one foot candle.

Foot candle definition3

Foot CandleDefinition

  • The one square foot surface area is exactly one foot in distance from the light source. The surface area is actually semi-spherical to keep all sections one foot in distance from the light source.

Foot candle definition4

Foot CandleDefinition

  • A light meter is used to measure the foot candle level of a scene.

  • A light meter incorporates a photo-sensitive cell that creates an electrical current when light falls upon it.

  • The current increases as the level of light falling on it is increased.

Foot candle definition5

Foot CandleDefinition

  • The meter will display the foot candle level in either a digital form or as a needle moving along an incremental scale. The meter uses the electrical current level as a reference to the level of footcandles that is falling onto the photo-sensitive cell. The higher the current the higher the footcandle reading.

Foot candle definition6

Foot CandleDefinition

  • The metric reference for light level is known as Lux. One lux equals the total intensity of light that falls on a one square metre surface that is placed 1 metre away from a point source of light that equals 1 candle power.

Visible spectrum spectral distribution

Visible SpectrumSpectral Distribution

  • The visible spectrum is a small portion of the electromagnetic spectrum. The entire spectrum includes electromagnetic waves such as gamma rays, x-rays, ultraviolet, infrared, microwaves, radio and television waves. Light waves vary in length and are measured in nanometres (nm) equal to one billionth of a metre. The wavelength determines the colour of visible light produced.

Visible spectrum spectral distribution1

Visible SpectrumSpectral Distribution

  • Short wavelengths are located in the violet portion of the spectrum, following the shorter ultraviolet waves. As the waves lengthen, they produce the remainder of the visible spectrum. The longest visible waves reside in the red portion of the spectrum prior to the invisible infrared waves.

Visible spectrum spectral distribution2

Visible SpectrumSpectral Distribution

  • Light sources use varying amounts of the visible spectrum to produce "white light". A tungsten incandescent studio lamp has very little of the violet waves, while large portions of the yellow to red wavelengths are used. An incandescent source produces high levels of infrared waves. They create more heat than light.

Visible spectrum spectral distribution3

Visible SpectrumSpectral Distribution

  • Arc sources, such as fluorescents and HMI, use specific portions of the spectrum. The spectral distribution of an arc shows the spikes of waves that are incorporated in this type of light source. Arcs sources, HMI & Xenon, have ultraviolet waves within their spectrum. Protection from these UV waves is necessary when using these sources. Manufacturers include a trip switch in lighting units that use these type of arc sources. Opening the lens, which blocks the UV, will trip the switch and shut off power to the bulb.

Visible spectrum spectral distribution4

Visible SpectrumSpectral Distribution

Colour mixing

Colour Mixing

  • "White light" is actually the combination of all colours from the visible spectrum. A prism illustrates this when it separates white light into the individual spectral colours.

Colour mixing additive mixing of colours

Colour MixingAdditive Mixing of Colours

  • The mixing of separate coloured light sources will create a new colour. When two or more light sources, of varying colours, are overlapped they "add" their specific light waves to combine with the other light source light waves.

Colour mixing additive mixing of colours1

Colour MixingAdditive Mixing of Colours

  • As the following example illustrates, a blue light's output added with a red light's output creates a magenta light. The primary colours of light are red, blue and green. Theoretically, if three light sources using primary red, green and blue gels are overlapped on a white surface, the intersection of all three beams will produce white light.

Colour mixing additive mixing of colours2

Colour MixingAdditive Mixing of Colours

Colour mixing subtractive mixing of colours

Colour MixingSubtractive Mixing of Colours

  • Coloured gel subtracts light waves, produced by the light source, and only allows a specific range of waves to pass through it. A primary red gel will stop light waves that are not within the red range of the spectrum, while allowing red waves to pass through it.

Colour mixing subtractive mixing of colours1

Colour MixingSubtractive Mixing of Colours

  • Gel manufacturers indicate, in their gel swatch books, the range of light waves that will pass through the specific colour of gel. A diagram, showing the spectral curve a "white" light will produce after passing through the gel, accompanies each sample gel. Tungsten light at 3200 degrees Kelvin is used as the reference "white" light that will be passing through the gel. Most objects, that are not light sources, use the subtractive process to appear their specific colour.

Colour mixing1

Colour Mixing

  • A blue ball receiving all the light waves from a "white" light source. The ball reflects only the blue range of light waves, while absorbing the other light waves in the spectrum.

Colour mixing2

Colour Mixing

  • This is important to remember when selecting the colour of light you choose to light an object. A red light does not supply the blue waves a blue ball needs to reflect, in order to appear blue.

  • A blue ball with only a red light source will appear black.

Creating depth in a 2 dimensional surface

Creating Depth in a2-Dimensional Surface

  • The television picture tube is a two dimensional surface that attempts to recreate the three dimensional world around us.

  • The dimensions of height and width are physical components of the picture tube. The third dimension, depth, must be created within the picture.

Creating depth in a 2 dimensional surface1

Creating Depth in a2-Dimensional Surface

  • Lighting plays a major role in creating the illusion of this third dimension. The size, perspective and clarity of an object also play a role in creating a third dimension, but for now we will concentrate on the role of lighting.

Creating depth in a 2 dimensional surface2

Creating Depth in a2-Dimensional Surface

  • The following examples show how a two dimensional circle can be transformed into a three dimensional ball using some basic lighting principles.

Creating depth in a 2 dimensional surface3

Creating Depth in a2-Dimensional Surface

  • Figure 1: Illustrates a ball in a two dimensional world; the ball has height and width only. The red of the ball can be referred to as the base tonal value of the object. This "flat" ball represents a three dimensional surface being lit directly from the camera lens angle. This style of lighting creates a flat appearance of an object.

Creating depth in a 2 dimensional surface4

Creating Depth in a2-Dimensional Surface

  • Figure 2 : We perceive dark portions of an object as being further away from us, while lighter portions appear closer.Shading one side of the ball, by placing the main light high and to the right of the camera lens, creates a dark shadow area that is perceived to be further away than the lighter area of the ball.

Creating depth in a 2 dimensional surface5

Creating Depth in a2-Dimensional Surface

  • Figure 2 : The shadow's transition (the edge between the base tonal value of the object and the darkness of the shadow) will vary with the type of main light source used.

Creating depth in a 2 dimensional surface6

Creating Depth in a2-Dimensional Surface

  • Figure 2 : A softlight will create a wide shadow edge with a gradation between the base tonal value and the darkest portion of the shadow.

  • A hard light will create a defined shadow edge with very little gradation between the base tonal value and the darkness of the shadow.

Creating depth in a 2 dimensional surface7

Creating Depth in a2-Dimensional Surface

  • Figure 2 : A Lighting Director's choice between a hard or softlight source, as the main light source, will influence the degree of gradation between base tonal value and the darkness of the shadow.

Creating depth in a 2 dimensional surface8

Creating Depth in a2-Dimensional Surface

  • Figure 3 : An objects highlight (the reflection of the originating light source within the object) gives an indication to the surface texture of that object.

Creating depth in a 2 dimensional surface9

Creating Depth in a2-Dimensional Surface

  • Figure 3 : Like the shadow edge, the highlight's edge will have a transition from the object's base tonal value to the brightest portion of the highlight. The highlight's transition edge will be wide when the object's surface has a matte or rough finish. When the surface has a polished smooth finish, the highlight edge can be sharp with little or no transition between tonal value and the bright portion of the highlight.

Creating depth in a 2 dimensional surface10

Creating Depth in a2-Dimensional Surface

  • Figure 3 : The polished smooth surface acts like a mirror reflecting the exact shape of the originating light source. In this example, if the ball's surface were polished smooth and the main light source was a window, the highlight would show a reflection of the exact square shape of the window.

Creating depth in a 2 dimensional surface11

Creating Depth in a2-Dimensional Surface

  • Figure 4 : The object itself must cast a shadow to show its spatial relationship to the world around it.The ball's shadow in this example gives the impression it is sitting on a surface. The lack of an object shadow, as in figure three, gives the impression the ball is floating in space without any relationship to its surroundings.

Creating depth in a 2 dimensional surface12

Creating Depth in a2-Dimensional Surface

  • Figure 4 : The object's shadow edge will also have a transition between the darkest portion of the shadow and the lighter portion of the surface it is cast upon. Again the width of this shadow edge transition will be determined by the type of main light source, hard or soft light, and the distance the main source is from the object.

Creating depth in a 2 dimensional surface13

Creating Depth in a2-Dimensional Surface

  • Figure 4 : A softlight source creates a wide shadow edge transition while a hard light creates a narrow shadow edge transition. A light placed close to the object creates a wider shadow transition than a light placed further away from the object.

Creating depth in a 2 dimensional surface14

Creating Depth in a2-Dimensional Surface

  • Figure 4 : The length of the object's shadow will relate to the placement of the main light source.

  • In this example, had the main light source been placed to the bottom right of the ball, the shadow would have been longer.The highlight will also reposition itself within the object when the main light source is moved.

Creating depth in a 2 dimensional surface15

Creating Depth in a2-Dimensional Surface

  • How a two dimensional circle can be transformed into a three dimensional ball using some basic lighting principles.

Angles of light positioning the light

Angles of LightPositioning the Light

  • One of the most critical decisions a Lighting Director makes is the position of the light source. An object's form will be defined differently depending on the shading and highlights created by the light source. What is not lit is as important as what is lit.

Angles of light positioning the light1

Angles of LightPositioning the Light

  • The following animation shows the affect of a single hard light source placed at various positions. We can relate the position of the light source to the hour positions on a clock face. As the light source moves around the clock the form of the person in the centre of the clock will change, from a dramatic figure in the ten and two o'clock position, to a flatly lit full figure in the six o'clock position.

Angles of light positioning the light2

Angles of LightPositioning the Light

  • This example applies to the height of the light source from the floor also. A source placed low to the ground in a ten o'clock position will have a different look to a source placed high in the ten o'clock position.

Angles of light position terms

Angles of LightPosition Terms

  • Terms vary depending upon the Country; stage or studio; single camera or multi-camera lighting.

Angles of light position terms backlight

Angles of LightPosition Terms - Backlight

  • A light source placed in the ten, twelve or two o'clock position in this example would be considered a backlight. The backlight highlights the shoulders and the hair of the person. It is used to separate the subject from the background. A single source backlight is usually placed in the twelve o'clock position. Two sources can be used for backlights but they would not be positioned beyond the three and nine o'clock position, as the light would fall upon the subject's face.

Angles of light position terms kicker

Angles of LightPosition Terms - Kicker

  • This term is often used in a single camera shoot when a single source is placed in the nine, ten, twelve, two or three o'clock position. In the nine and three o'clock position the kicker would be a side kicker because it would be intended to fall upon the face. Unlike a backlight a kicker can fall upon the face depending upon the look the lighting director intends.

Angles of light position terms keylight

Angles of LightPosition Terms - Keylight

  • A light placed in the four, six or eight o'clock position would be a keylight. The keylight defines a subject's form by creating the main shadows and highlights. The keylight position is often placed to one side of the camera, eight or four o'clock position, to create depth.



  • A softlight creates a shadow that has a less defined edge, compared with a hard light's defined shadow edge.

  • A hardlight's shadow edge mimics the image that is casting the shadow (dependent on the light source, object, shadow distances).



  • The hard light acts like a single point source of light. However, the softlight acts like a multitude of point sources with each point source cancelling out each other's defined shadow.



  • The size of the softlight has a major influence on how defined the shadow's edge will be. The larger source allows the multitude of point sources to wrap around an object and cancel out the effects of the point sources that are creating the shadow.



  • If you wish to create a less defined shadow, the physical size of a softlight is one aspect to consider. The physical distance the softlight is placed, to the object that will be casting the shadow (as the following examples illustrate), affects the shadow edge. When you move a soft source closer to an object, you actually increase the size of the softlight in relationship to the object.



Close Distance Medium Distance Far Distance

When you move a soft source closer to an object, you actually increase the size of the softlight in relationship to the object.



  • A hard source can be made into a soft source by either "bouncing" (pointing the light towards a surface) against a white card, or by placing a piece of diffusion gel in front of the hardlight. This actually transforms this single point source into a multitude of point sources.



  • When placing a diffusion gel on the barndoors of a hardlight, the gel itself now becomes the light source. This means that the barndoors are now just a gel holder. Unwanted light (emanating from the gel) must be blocked with flags or blackwrap



  • The edge of a shadow is noticeable on a face. A nose shadow falling on a cheek, for example, will be less defined if we use a large soft source. The choice between a hard light source and a soft light source will be determined, by the Lighting Director, depending on the mood or textures he/she is try to achieve.

Lighting levels the camera

Lighting LevelsThe Camera

  • 2/3" CCD camera sensitivity, using Hyper HAD CCDs ('f8' camera)

  • At f4.0 requires 750 lux

  • At f2.8 requires 375 lux

  • At f2.0 requires 187.5 lux

Lighting levels the camera1

Lighting LevelsThe Camera

  • For talking head programmes, using prompting devices, aim for 500-600 lux.

  • For that Light Entertainment feel, aim for about 800 lux and use 0.3ND filter in the camera filter wheel or minus gain to get good optical separation.

Lighting levels the luminaires

Lighting LevelsThe Luminaires

  • Beam angle is the angle between half intensity points. Reduce by 10° to get useful coverage angle.

  • Illuminance (lux or lumens/m2) = Candlepower (candelas)/Distance2 (metres)

Lighting levels notes

Lighting LevelsNotes

  • To take into account ageing, dirt, etc. reduce manufacturers quoted candlepower by 15% - 20%

  • For large angles of incidence multiply by Cosine of this angle e.g. for 30° reduce by 14% (cos 30° = 0.86)

  • When tele prompter fitted to camera, sensitivity is reduced by about ½ stop (70% transmission)

Lighting levels notes1

Lighting LevelsNotes

  • x2 range extender loses 2 stops of sensitivity (x 0.25)

  • Be aware of zoom ramping with long focal length lenses and open apertures i.e. f 2.0

  • Minus blue filter (filter 3) reduces sensitivity by almost 1 stop

Lighting levels notes2

Lighting LevelsNotes

  • +3dB is equivalent to + ½ stop (x 1.4)+6dB is equivalent to + 1 stop (x 2)+9dB is equivalent to + 1½ stop (x 2.8)-3dB is equivalent to - 1½ stop (x 0.7)-6dB is equivalent to - 1 stop (x 0.5)-9dB is equivalent to - 1½ stop (x 0.35)

  • ASA rating = (1250 x f no.2 /illuminance (foot candles)) * (1/50 sec exposure time)

Lighting level

Lighting Level

  • At the planning stage an estimate of the required lighting level should be made. Clearly, if working out of doors this will be difficult to predict with any accuracy but “time-of-day/time-of-year” should help to some extent.

Lighting level1

Lighting Level

  • One should consider:-

  • Basic camera sensitivity at required aperture.

  • Tungsten/Daylight considerations.

  • Zoom ramping.

  • Use of range extenders.

  • Use of prompt devices.

  • Existing lighting conditions.

Lighting level2

Lighting Level

  • Often, depending on a programme content/location, the lighting will need to “modify” the natural lighting to make it more acceptable for recording. So one should be prepared for a wide range of lighting possibilities.

Lighting on location

Lighting On Location

  • Lighting on location involves a similar process to the studios, namely planning, rigging/setting of luminaires and final balance of their relative intensities.

Lighting on location1

Lighting On Location

  • The major difference is that whereas in a studio, one is working in a “controlled” environment, on location there is usually very little control of the weather - it is difficult to predict and impossible to control. So, when working on location one has to be prepared for a wide range of possible conditions.

Lighting on location reconnaissance

Lighting On Location Reconnaissance

  • There should be some form of reconnaissance (recce) of the location prior to the day of the actual shoot. This is to ensure that there is time to solve the problems which the site may pose or to decide that the location is totally impossible to light or shoot or cover for sound and therefore another site must be found.

Lighting on location reconnaissance1

Lighting On Location Reconnaissance

  • At this early planning stage, it is important that the Director supplies as much information as possible about the location and the action to be recorded.

Lighting on location reconnaissance2

Lighting On Location Reconnaissance

  • Artiste(s) position(s) and moves.

  • Camera(s) position and moves.

  • Shot sizes - dictating the area to be lit.

  • Multi-camera or single camera shooting.

  • Matching of shots to studio or other locations.

  • Method of sound pick up and probable position of microphone.

Lighting on location reconnaissance3

Lighting On Location Reconnaissance

  • Time of day for the shoot - where will the sun be?

  • Overall theme of action, e.g. Drama, Documentary, Variety.

  • Time scale of shoot.

  • Budget available for lighting.

Lighting on location reconnaissance4

Lighting On Location Reconnaissance

  • The problems to be found on location are very different to those of the studio, but of course one is still striving for pictures which are technically and artistically pleasing. The points to consider at the recce/planning stage are:

Lighting on location reconnaissance5

Lighting On Location Reconnaissance

  • Influence of natural lighting.

  • Colour temperature.

  • Lighting level.

  • Excessive contrast.

  • Power availability on site.

  • Cabling.

  • Luminaires.

  • Means of fixing luminaires.

Lighting on location reconnaissance6

Lighting On Location Reconnaissance

  • Dimmers I control system.

  • Number of Electricians.

  • Times scale.

  • Picture monitor.

  • Budget.

  • Communication.

  • Access to the site/building.

  • Safety.

Influence of natural lighting

Influence of Natural Lighting

  • What will be the possible range of lighting conditions existing at the time of the shoot?

  • Will it be day, night, early morning or late evening?

  • Where will the sun be during the period of the production?

  • Consider all these points and decide how best you can use the natural lighting to best advantage, i.e. as main source light, filler or back-light.

Influence of natural lighting1

Influence of Natural Lighting

  • Then establish what lighting is required to supplement the natural lighting to make the pictures acceptable.

  • Remember though, that “daylight” can change rapidly and is difficult to predict, so be prepared to meet a wide range of lighting conditions, i.e. bright sun through to dull overcast.

Influence of natural lighting2

Influence of Natural Lighting

  • Continuity of lighting conditions may also require one to create a “bright sun” on an overcast day. Clearly this is impossible on landscape shots, but on limited area exteriors and interiors, this is possible if the right light sources are available.

Influence of natural lighting3

Influence of Natural Lighting

  • In some instances of interior shooting, the influence of daylight may be minimal such that one can ignore it completely, i.e. very little daylight entering the room and windows not in shot.

Colour temperature13

Colour Temperature

  • The first consideration is usually that of colour temperature. Unless one is trying to obtain a particular effect, it is important to operate with light sources which are all approximately of the same colour temperature. So, when deciding to operate in a Daylight environment, ideally all sources should produce Daylight or be colour temperature corrected to look like Daylight. Similarly, if one decides to operate in a Tungsten mode, all sources should be Tungsten or corrected to Tungsten.

Colour temperature14

Colour Temperature

  • It is worth noting that the above two options are not the only ones. For example if one has a mixture of light sources, it may be more efficient to correct them to some mean value, thereby reducing the losses introduced by full correction.

Colour temperature15

Colour Temperature

  • Or, it may be acceptable that any exterior Daylight appears slightly blue thus interior tungsten lights could be corrected to ½ CTB (and white balance to ½ CTB), this would reduce the loss which would have been introduced by using a full CTB filter.

Colour temperature16

Colour Temperature

  • Or, on the other band, it may be acceptable or even desirable that tungsten practicals should look warm (and not white). In which case all “daylight” needs to be corrected with ½ CTO filters.

Colour temperature17

Colour Temperature

  • Where one has visible exterior daylight and “practical” tungsten sources, it may be acceptable to also operate In a halfway condition. In which case, all tungsten sources (excluding practicals) should be corrected to ½ CTB and all daylight sources corrected to ½ CTO (excluding windows).

Colour temperature18

Colour Temperature

  • All “in-shot” practicals (tungsten) will then appear “warm” and, “in-shot” windows will appear “cold”, i.e. slightly blue, provided of course that the camera has been white-balanced to a white point half-way between tungsten and daylight.

Lighting level3

Lighting Level

  • At the planning stage an estimate of the required lighting level should be made. Clearly, if working out of doors this will be difficult to predict with any accuracy but “time-of-day/time-of-year” should help to some extent. A discussion of factors affecting lighting levels is covered on a separate, more detailed note -however, to summarise one should consider:

Lighting level4

Lighting Level

  • Basic camera sensitivity at required aperture.

  • Tungsten/Daylight considerations.

  • Zoom ramping.

  • Use of range extenders.

  • Use of prompt devices.

  • Existing lighting conditions.

Lighting level5

Lighting Level

  • Often, depending on a programme content/location, the lighting will need to “modify” the natural lighting to make it more acceptable for recording. So one should be prepared for a wide range of lighting possibilities.

Excessive contrast

Excessive Contrast

  • This often occurs on exterior work, the most common example is that of the face lit by the sun. In brilliant sunlight and no clouds, the contrast between the sunlit part of the face and the shadows will be excessive, i.e. 3 - 4stops difference giving a contrast of at least 8:1. To enable detail to be seen in the shadow areas one must add light either by using a reflector board to “bounce” the sun or by using an appropriate light source.

Excessive contrast1

Excessive Contrast

  • Always remember that the light levels from the sun can be extremely high. In studios the scene illumination is typically of the order of 1000 lux. On a bright sunlit day the scene illumination can be as high at 100,000 lux - a factor of x 100 studio levels. Consequently, one must choose the appropriate light source very carefully. A light source used for studio work at 5 metres, will have little effect at 5 metres out-of-doors on a sunlit day!

Excessive contrast2

Excessive Contrast

  • Video cameras can handle a scene contrast of approximately 40:1, film cameras approximately three times this value. The average exterior contrast is approximately 150:1 but it can be as high as 1000:1. Obviously care must be exercised in shooting to ensure that this excessive contrast does not spoil the picture. Close-ups of faces against bright skies can pose particularly severe problems.

Excessive contrast3

Excessive Contrast

  • This excessive contrast becomes even more of a problem when one moves inside and shoots against windows. The contrast between interior and exterior can be high - this is more of a problem with video cameras than film cameras because of the limited contrast handling ability and the “spreading” of high lights. It is usually impractical to light an interior to the same illumination as the exterior so Neutral Density filters need to be fitted to the windows.

Excessive contrast4

Excessive Contrast

  • These are available either as flexible gelatine filters or as 4 mm acrylic sheets. The range available is

  • 3ND (1 stop)

  • 6ND (2 stops)

  • 9ND (3 stops)

  • 1.2ND (4 stops)

  • Also available are combined ND filters and Colour Temperature Correction filters.

Excessive contrast5

Excessive Contrast

  • The ND filters should not be visible on camera - ideally, they should be stapled onto temporary wooden frames and fastened to the outside of the windows with simple wedges. Care should be taken to ensure that the location property is not damaged (if the filters are stapled directly into the window frames, all staples must be removed after the shoot and the damages holes repaired).

Lighting contrast ratios

Lighting Contrast Ratios

  • When using artificial light sources to illuminate a subject, a ratio between the relative intensity of the key light and the fill lights can be determined. First, the intensity of light is measured at the subject under both the key and fill lighting. Then the intensity of the fill light alone is measured. The ratio of the intensities of the combined key light and fill lights to the fill light alone, measured at the subject, is known as the lighting ratio.

Lighting contrast ratios1

Lighting Contrast Ratios

  • Portrait lighting ratios for colour photography are typically around 3:1 or 4:1. For instance, let's suppose that you were using a film stock rated at EI 400 and you've lit your subject with typical key-plus-fill to fill lighting.

Lighting contrast ratios2

Lighting Contrast Ratios

  • If the combined key light plus fill light produce an incident meter reading of T5.6 (100 footcandles) and a reading of the fill light alone measures T2.8 (25 footcandles), the ratio would be 4:1 or a two stop difference from the highlights to the shadows.

Illumination incident light for camera films

Illumination(Incident Light) for Camera Films

  • Illumination (incident Light) Table When the illumination is very low or where reflected-light measurements cannot be made conveniently, you can use an incident-light meter to read the illumination directly in footcandles (lux). The following illumination Table gives the correct aperture setting for a given exposure index and a given footcandle (lux) reading.

Illumination incident light for camera films1

Illumination(Incident Light) for Camera Films

  • The values are intended for use with tungsten light or with daylight, depending on the balance of the film. The values given refer to measurements with a meter held at the subject position and the integrating sphere pointed directly toward the camera.

Illumination incident light for camera films2

Illumination(Incident Light) for Camera Films

  • The values assume exposure by the recommended illuminant (daylight or tungsten) without filtration. In the following summary of illumination tables from the datasheets, the films are listed in decreasing order of exposure index (EI).

Introduction to technical operation video editing

Illumination (Incident Light) for Camera Films Using Recommended Illuminant Exposure Time 1/50 second (24 fps)

  • Values in the following table are given in footcandles.

Lighting contrast ratios3

Lighting Contrast Ratios

  • When using artificial light sources to illuminate a subject, you can determine a ratio between the relative intensity of the key light and the fill lights. First, measure the intensity of light at the subject under both the key and fill lighting. Then measure the intensity of the fill light alone. The ratio of the intensities of the combined key light and fill lights to the fill light alone, measured at the subjects, is known as the lighting ratio.

Lighting contrast ratios4

Lighting Contrast Ratios

  • Except for dramatic or special effects, the generally accepted ratio for colour photography is 2 to I or 3 to 1. If duplicate prints of the camera film are needed, the ratio should seldom exceed 3 to 1.

Lighting contrast ratios5

Lighting Contrast Ratios

  • For example, if the combined main light and fill light on a scene produce a meter reading of 6000 footcandles at the highlight areas and 1000 footcandles in the shadow areas, the ratio is 6 to 1. The shadow areas should be illuminated to give a reading of at least 2000 and preferably 3000 footcandles to bring the lighting ratio within the permissible range.

Lighting contrast ratios6

Lighting contrast ratio 5:1

Lighting contrast ratio 2:1

Lighting Contrast Ratios

Fresnel from 1954

FRESNEL(From 1954)

  • This spotlight uses-a “Fresnel” lens, named after its french physicist inventor (Augustin Fresnel 1788-1827). The Fresnel is a convex lens thinner than a normal lens with the same focal length-achieved by making the surface a series of stepped concentric rings, each with the same curvature as the equivalent normal convex surface at that radius.



  • This trick diffuses the light-beam (to soften the beam and to prevent the lamp-image being projected) AND (because of its thinness) avoids the light-absorption that the Focus-Spots’ lenses suffered from. The Fresnel lens is also employed in lighthouses. In that guise it consists of an enormous series of separate rings and is so heavy, that it is commonly supported in a bath of mercury.

What s a fresnel


  • A point light source, such as a lamp throws out light in all directions. By placing a piano-convex lens in front of the source, the rays can be controlled and directed to where we want them. The main problem is that the lens has to be large in order to capture as much of the light as possible.

What s a fresnel1


  • At some point it was noticed that there’s a large volume of glass in the centre of this lens which isn’t actually doing anything. So, if you were to slice up the simple lens and remove this glass...

What s a fresnel2


  • .and paste the remaining bits back together, you’d get a much lighter lens which still focussed the light, yet was thin enough to disperse the heat and at the same time weighed a lot less. The result is a pleasantly soft yet adjustable beam of light.



  • The first British Fresnel lantern was Strand’s 500 watt Pattern 123, which was produced from about 1954. It was followed by the 1Kw 223 and the 2Kw 243. The advent of this lantern revolutionised the look of the stage. Light could now be accurately focussed into specific areas, and beams from different spots merged into one-another to produce a general cover”.

Studio 2 kw quartz halogen fresnel

STUDIO 2 kWQuartz Halogen Fresnel

Distance (m)

3 5 10 15

Strand Lighting

Arturo softlights 1250w

ARTURO Softlights1250W

Distance (m)

3 4 5 6

Strand Lighting

Arturo softlights 2500w

ARTURO Softlights2500W

Distance (m)

4 5 6 7

Strand Lighting

Redhead 800w

Redhead 800W

Distance (m)

3 4 5 6

Strand Lighting

Blonde 2000w

Blonde 2000W

Distance (m)

3 4 5 6

Strand Lighting

Different types of lighting

DifferentTypes of Lighting

Video pro banks

Video PRO Banks

  • For controlled soft lighting on small sets, or for use as a separation light or small fill. These standard-depth banks are extremely light weight and are primarily used with single broad-beamed, open-faced instruments.

Daylite junior plus bank

Daylite JuniorPLUS Bank

  • Intended for use with smaller, narrow-beam instruments, such as 1,000 watt Fresnels and Mickey Moles.

  • As much as 50% deeper than Video PRO Banks, Junior Banks produce a superb light quality while yielding the maximum output from your narrow-beam instruments.

Chimera lantern

Chimera Lantern

  • This high-tech version of the traditional Chinese lantern serves well as a central soft light for round-table interviews and for filling interior shooting spaces with soft, ambient light.



  • Aurasoft reflector consists of thousands of tiny spheroidal convex mirrors, each reflecting angled light across the path of the adjoining mirror.

  • The thousands at individual light beams criss-cross one another and reduce the directness of the light, creating an effect of quite surprising natural softness. To enhance this softness and to minimise interference from moiré patterns, the thousands of individual mirrors have been employed in a range of different diameters.



  • The result gives a soft natural light, with virtually the same soft shadows that are associated with a natural skylight.

  • The unique reflector design produces an even spread of light across an exceptionally wide area.

Aurasoft 600

Aurasoft 600

  • 1kW/2kW/3kW Tungsten Halogen

    Light Output @ 5m:

    1kW, 180 lux; 2kW, 360 lux; 3kW,

    550 lux (open face)

    Illumination Angle

    (0.5% intensity):70º (open face)

    (0.1% intensity):116º (open face)

Aurasoft 800

Aurasoft 800

  • 2kW/4kW Tungsten Halogen

    Light Output @ 5m:

    2kW, 280 lux; 4kW, 510 lux (open face)

    Illumination Angle

    (0.5% intensity):70º (open face)

    (0.1% intensity):130º (2kW open face);

Inverse square law the cosine law

Inverse square lawThe cosine law

  • Two important laws should not be overlooked here when deciding on the luminaire to use, namely - the inverse square law and the cosine law.

Inverse square law the cosine law1

Inverse square lawThe cosine law

  • Luminaire manufacturers publish data on the performance of their product. Remember that this data will be for a new luminaire/new lamp (bulb) combination connected directly to the mains. So, take account of possible ageing of luminaire/lamp, actual lamp throw” (not the horizontal distance) and the Cosine law.

Inverse square law the cosine law2

Inverse square lawThe cosine law

  • In this example, the light source makes an angle of incidence of 45° on the subject.

( / 2 x d )

The actual lamp throw will be:

( / 2 x d ) [ d = Horizontal Distance ]



Inverse square law the cosine law3

Inverse square lawThe cosine law

  • If the candle-power of the light source is I Candelas the illumination on the subject will be:

Inverse square law the cosine law4

Inverse square lawThe cosine law

  • Subject illumination (E)

    = IxCos 45 lux

    ( / 2 x d)²

    = I x O.7 lux

    2 x d²

    = Ix O.35 lux

Inverse square law the cosine law5

Inverse square lawThe cosine law

  • If one had ignored the Cosine factor and the true throw, the calculated illumination would be:


Inverse square law the cosine law6

Inverse square lawThe cosine law

  • So the true illumination would be only 35% of the value calculated ignoring the true throw and Cosine law - an error of 65% !

  • With a 30º keying angle, the error involved would be approximately 37%, clearly these are factors which must not be ignored !

Direct and alternating current

Direct AndAlternating Current

  • Electric supplies are of two types: direct and alternating. In the former the current flows always in the one direction, from the positive pole to the negative. Alternating current, on the other hand, reverses its polarity many times a second. The standard frequency in England is 50 cycles, which means to say that each wire of the circuit becomes successively positive and negative 50 times every second.

Direct and alternating current1

Direct AndAlternating Current

  • Large A.C. installations are generally wired on a three-phase supply. Here we have three wires, coloured generally red, white and green, the current in each of which reverses in polarity at different instants; in addition, there may be a fourth or neutral wire, generally black. The standard voltage in this country is 230 V single-phase or 415 V 3 -phase, either, as mentioned, 50 cycles.

Electric units

Electric Units

  • Let us draw a domestic analogy from the gas supply. When cooking the dinner we have low pressure.

  • In order to get the dinner ready on time, to compensate for this low pressure we turn the taps higher and burn more cubic feet of gas.

Electric units1

Electric Units

  • These terms of the gas engineer have their corresponding quantities in electricity. The unit of pressure is the volt, and the unit of current flow the ampere. The equivalent of the various factors which restrict the flow of gas - the length of pipes, and notably the gas - tap - is resistance, measured in ohms.

Ohm s law

Ohm’s Law


= amps




= ohms


Ohm s law1

Ohm’s Law

or equally

amps x ohms = volts

Ohm s law2

Ohm’s Law

  • Power obviously depends upon both the pressure and the amount of current. Consequently the unit of power, the watt, is equal to the product of pressure and current:

Ohm s law3

Ohm’s Law

watts = volts x amps

or alternatively –


amps =


Capacity of installation

Capacity of Installation

  • The load-carrying capacity of any circuit or sub-circuit is always reckoned in amperes. On switches, fuses, and the company’s meters one will generally find marked the permissible rating. How is one to ascertain how many lamps of given wattage can be safely run on a circuit rated at so many amperes?

Capacity of installation1

Capacity of Installation

  • Supposing it is desired to run, say, three 800 - watt lamps on a 240 - Volt supply ?

Capacity of installation2

Capacity of Installation

  • We first ascertain the total wattage, which equals 2400, and, dividing by 240, we get the answer 10 amperes.


    = 10 amps


Power availability on site

Power Availabilityon Site

  • This is an obvious planning requirement - to investigate the mains power available on site and how much can be used for the Outside Broadcast/Location work. If there is insufficient power available then one would need to supplement it with a mobile generator or simply use a generator by itself.

Power availability on site1

Power Availabilityon Site

  • When considering mains power, one should also try to evaluate how “good” the mains feed is. For example, In remote areas it is quite common for the mains to be more than 15% down on nominal voltage when supplying a large load. This will result in a significant drop in light output of the luminaires.

Power availability on site2

Power Availabilityon Site

  • Allied to availability of a good mains supply, will be accessibility of the main bus-bars to make the appropriate connections to the location lighting equipment.

Power availability on site3

Power Availabilityon Site

  • The current demand by discharge sources should be noted in calculating total “demand”. HMI sources do not follow the normal power equation:-

  • P = IV Watts

Power availability on site4

Power Availabilityon Site

  • Typically, a 2½ Kw HMI draws 14.5 Amps and not 10.4 Amps as one might expect for a 2½ Kw load.

  • The starting current for HMI sources should also be noted - again a normal 2½ Kw HMI source takes 32 Amps on starting.

Power availability on site5

Power Availabilityon Site

  • Flicker-free HMI sources take more current than the normal HMI, e. g. a “flicker­free” 2½ Kw HMI running current is 19.6 Amps.

  • Allow a good “headroom” on supplies of unknown reliability, otherwise, if working near to the limit of the supply an embarrassing power failure may result.

Power availability on site6

Power Availabilityon Site

  • Careful planning of load requirements is essential to ensure that the mains supply / generator is capable of coping reliably.



  • Cable routes for mains cables (also camera & sound cables) should be planned to ensure:

  • Shortest possible route consistent with no cables “in-shot”.

  • Minimum disturbance to the general public.



  • Minimum disturbance to access, i.e. paths/roads.

  • Security of the location is not jeopardized, i.e. windows can be closed at night.

  • Avoid mains cables and sound cables running parallel.



  • The choice of luminaire will depend on:

  • Daylight/Tungsten.

  • Scene illumination required.

  • Lamp throw required.

  • Area to be lit.

  • Control of the beam shape required.



  • Luminaires available.

  • Power available.

  • Suspension system / luminaire weight.

  • Time scale.

  • Budget

Means of fixing luminaires

Means of Fixing Luminaires

  • This is the area which often requires a certain amount of ingenuity to get the luminaire where you want it. The simplest method would be on a stand, but the range of other possibilities include:

  • Turtle

  • Low Stand

  • Medium Stand

  • Extra High Lift Stand

Means of fixing luminaires1

Means of Fixing Luminaires

  • Genie Stand

  • Scaffold Tower or Scaffold Bar

  • Lightweight Trussing (Trylite)

  • Heavy Trussing

  • G Clamp & Spigot

  • Lite-Beam

  • Aerial platform (“cherry-picker” type vehicle)

  • Scissor lift

Means of fixing luminaires2

Means of Fixing Luminaires

  • “Pole-Cats” (lightweight fittings only)

  • Beam Clamp (lightweight fittings only)

  • Gaffer Grip (lightweight fittings only-Italian Clamp)

  • Lightweight Gaffer Grip (lightweight fittings only)

  • Scissors clamp (lightweight fittings only)

  • Super clamps/magic arms

  • Dimmers / Control Systems

Dimmers control systems

Dimmers / Control Systems

  • When operating with Tungsten, it is extremely useful to have the facility of dimmers on all lighting circuits. This enables swift balancing of lighting levels and allows for “on-shot” lighting changes to be made.

Dimmers control systems1

Dimmers / Control Systems

  • Flicker-free” HMI sources can be dimmed electrically to about 40% of their maximum light output. If full dimming is required then mechanical dimmers have to be fitted to each luminaire - these can be controlled via a servo-system or more commonly by an Electrician. (If using a large number of HMI’s this could become expensive and complicated 1 Electrician/luminare plus talkback facilities to each Electrician)

Dimmers control systems2

Dimmers / Control Systems

  • If portable dimmers are used they should be sited well away from the “action area" to avoid interference with sound pick-up. (Some units buzz when dimmed).

Number of electricians

Number of Electricians

  • This will depend on the size of the job,i.e.

  • Number of luminaires to be rigged and their weights.

  • Cable runs.

  • Site difficulties - high mounting positions for luminaires.

  • Generators being used.

Number of electricians1

Number of Electricians

  • Time scale.

  • Budget.

  • The last two items are clearly related, one has to design the lighting treatment to fit in with the requirements of both timescale and budget.



  • It is very important to establish a reasonable timescale for any production. This is something which win mainly be based on past experience and the particular production requirements. Do not forget timescale for the de-rig operation!

Picture monitor

Picture Monitor

  • It is extremely useful to have a colour picture monitor available adjacent to the camera position. This is especially helpful when shooting location work to a short timescale and avoids the need to be continually running back to the control vehicle to check picture content.



  • This is the factor which will have the greatest influence on the production - it will dictate timescale/manpower/ technical resources available for the programme. It must be known at an early stage.



  • Good communication is vital to the speed and efficient working of any team. There should be some form of radio communication available, in addition to normal talkback, to enable the Lighting Director to speak with the Foreman Electrician, Vision Control and when used, Follow-Spot Operators.



  • At the planning stage investigate access to the location, local contacts. Note any problems which might affect the rigging or de-rigging, e.g. religious services at various times of the day or possible extra requirements for total quiet.



  • An absolute essential. Any location lighting must be within the local Electrical Safety Regulations. Particular hazards to watch out for are:

  • Electrical earthing.

  • Correct use of isolating transformers.

  • All stands, scaffolding correctly erected. Safety aspects of 3 phase supplies.



  • Suspended luminaires - safety bonds (also safety bonds on non-captive barndoors).

  • Damage to the location site from heat due to luminaires being too close to curtains, ceilings, paintings and other works of art.



  • Always ask at the “recce” if there are any particular features of the location with which one should be especially careful.

At the recce

At the “Recce”

  • Listen to Director/Producer.

  • Collect all the information you require.

  • Observe natural lighting of location.

  • Measure existing lighting levels.

  • Measure existing contrast levels.

  • Measure dimensions of the location, as necessary, e. g. area and height.

At the recce1

At the “Recce”

  • Observe where lighting units may be suspended.

  • Decide on cable runs.

  • Decide on location of dimmers (if used) and generator (if used).

  • Verify mains supply capability.

  • Safety aspects should be considered at all times.

Useful items at the recce

Useful Items at the “Recce”

  • Clip-board, notepad, pencil and eraser. Exposure meter.

  • Spotmeter.

  • Tape measure, ideally a retractable steel ruler, to enable easy measurement of heights and location dimensions.

Useful items at the recce1

Useful Items at the “Recce”

  • Small digital camera to record features of the location for future reference.

  • Small torch - to help investigate mains supply connections in dark cupboards!

  • Small compass - useful in establishing position of the sun on overcast recce days!

Pre production

Pre – Production

  • When producing any form of media i.e. Documentary, Docu soap, Drama, Comedy, TV commercial - firstly you need an idea!

  • Once you have that idea, you need to translate it into a form that can be made feasible to view by your ultimate audience.

  • It may be that the ‘idea’ already exists from your client or colleague. If so, the next step is RESEARCH

Pre production1

Pre – Production

  • The first step of research is TALK. Talk to the author or client, the participants, the experts who have knowledge of the subject matter.

  • They should give you enough working material to develop your perception on how you will put the message across – and how you will tell the story.

  • If you need further material, statistics, opinions - find an alternative source. eg. Libraries/Internet/Newspapers/ Technical journals.

Pre production2

Pre – Production

  • At the same time as carrying out research, give the project an identity (a ‘working title’). This will not necessarily be the final title on the captions but will give the programme a flavour of its content.

  • When you feel that enough research is done, the next step is the -TREATMENT.

  • The Treatment is an outline of the programme’s content and running order. A portrayal of how you will interpret the subject matter into a visible and audible form.

Pre production3

Pre – Production

  • The Treatment should be laid out as an introduction to the project brief (Preamble) and lead into a description of the programme content stating how you will tell the story, what visuals/audio elements will be included and the style that will be followed.

  • If the client agrees with the Treatment the next task is a COSTING/BUDGET proposal.

Pre production4

Pre – Production

  • The COSTING should include every element of Production :-

  • Director / Producer fee

  • Scriptwriter fee

  • Presenter / voiceover fees

  • Camera crew & equipment hire / tapestock / transport

  • Lighting hire / transport

Pre production5

Pre – Production

  • Hotel Accommodation / Rail (Air) fares?

  • Royalties for library footage?

  • Studio hire fees

  • Post production costs (EDITING)

  • Video duplication costs

  • Special effects. . .Autocue. . .

  • Can you think of any others?

Pre production6

Pre – Production

  • Once the budget is agreed we move on at last, to writing the SHOOTING SCRIPT.

  • This may incorporate changes several times during production but the first draft is always the starting block. . .

  • It can be laid out in Two column form with PICTURE content (left) and

  • AUDIO content (right)

Pre production script layout

Pre – ProductionScript Layout

(Left) visuals(Right) audio

1. Description of location/Narration / music / fx

shot detail / captionsat this point

2. As aboveAs above

And so on. . .

Remember to number each visual /audio paragraph.

Production camera shooting technique

ProductionCamera Shooting Technique


Some DO's and DONT's

Production camera shooting technique1

ProductionCamera Shooting Technique

  • ALWAYS use a tripod where possible (unless the use of handheld camera is desired/essential for effect)

  • Make sure the tripod is locked down and LEVEL (use the heads spirit level) Focus at full zoom and then widen the shot to desired image size.

  • Check exposure using ZEBRA and set to manual exposure, to avoid the iris hunting up and down in changing light.

Production camera shooting technique2

ProductionCamera Shooting Technique

  • When panning or tilting, make the action smooth and come to a definite ‘stop’ at the end of the shot.

  • Only zoom when necessary/keep camera steady. i.e. LET THE SUBJECT MOVE WITHIN THE FRAME! avoid ‘hosepiping’

  • When filming people - avoid having their HEAD too low in the frame. Avoid ‘CRASH’ zooming - especially on documentary work.

Production camera shooting technique3

ProductionCamera Shooting Technique

  • Check you have selected the correct colour temp. filter and remember to White balance!

  • Set brightness/contrast in the camera viewfinder.

Production vox pops

ProductionVOX POPS

From latin


Production some do s and dont s vox pops

ProductionSome DO's and DONT'sVOX POPS

  • DO Use a tripod if possible.

  • DO decide on your story/questions in advance before approaching likely members of public. i.e. RESEARCH!

  • DO pick questions that can be answered briefly (and be answered in a self contained form of words) This will avoid having to use the Reporters questions each time when editing the audio.

Production some do s and dont s vox pops1

ProductionSome DO's and DONT'sVOX POPS

  • DO frame the Interviewee 'Head & Shoulders' at approx. eye level.

  • DO position the subject so they are not squinting into camera - eg in harsh sunshine.

  • -check exposure/zebra pattern.

  • DO mic the sound closely in busy/noisy areas to get a clear answer.

  • DO be ready to 'turnover' tape straight away (need 5-10 seconds run up if poss).

Production some do s and dont s vox pops2

ProductionSome DO's and DONT'sVOX POPS

  • DO keep questions brief and get a mix of sex/age/background of Interviewee (vary the type of person/answers you are likely to get a response from).

  • DO get some couples to interview, in a two shot (vary the background).

  • DO use answers that are concise so you can 'grab' quick sound bytes when editing.

Production some do s and dont s vox pops3

ProductionSome DO's and DONT'sVOX POPS

  • DON'T forget to get the camera level (use spirit level on the tripod).

  • DON'T forget to white balance for the prevailing light - with correct filter!

  • DON'T forget to record colour bars & line up tone at start of tape (-4db for 30 secs).

  • DON'T get the mic in shot (keep the shot medium tight).

Production some do s and dont s vox pops4

ProductionSome DO's and DONT'sVOX POPS

  • DON'T frame so that you get lamp posts or traffic signs etc. growing out of peoples heads/ears.

  • DON'T ask more than 2 or 3 questions - ideally one or two should do.

  • Remember tape is relatively cheap - don't be afraid to use it.


Introduction to technical operation video editing


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