4 Functions Controlled By Lens

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# 4 Functions Controlled By Lens

## 4 Functions Controlled By Lens

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##### Presentation Transcript

1. 4 Functions Controlled By Lens • Image focus- • Quantity of light- • Image area- • Depth of field-

2. 4 Functions Controlled By Lens • Image focus- 3 techniques? 1. Turn a ring on barrel of lens 2. Zoom in, set focus, zoom out 3. Tape measure: measure camera to subject distance, set ring accordingly

3. 4 Functions Controlled By Lens • Quantity of light- How do you determine f-stops? focal length ------------------ = f-stops lens diameter -focal length- distance from focal plane (film) to optical centre of the lens) *Remember: Lower # = Bigger Aperture

4. Quantity of Light • Fast Lenses=? -Larger maximum aperture -This leads to… -shorter (faster) exposure time -capable of very shallow DOF • Slow Lenses=? -Smaller maximum aperture -This leads to… -longer (slower) exposure time -NOT capable of very shallow DOF

5. 4 Functions Controlled By Lens • Image Area- Each focal length has a given angle of view: Short/Wide-21mm-35mm; curved/distorted “Normal”- 50mm; approximates human sight Narrow/Long-105mm-300mm; a.k.a. “telephoto,” creates a ‘flat’ image

6. 4 Functions Controlled By Lens • Depth of Field- -Zone of focus between closest and farthest parts of the picture that are reasonably sharp. -Controlled by three factors: – Lens Opening (Size of Aperture) -smaller aperture=greater DOF -thus, high f-stop=greater DOF – Focus Distance (camera to subject distance) -farther distance=greater DOF – Focal Length (lens to focal plane) -shorter focal length=greater DOF *Remember: Depth of Field extends about twice as far behind the plane at which the lens is focused as in front.

7. Depth of Field • What is hyperfocal distance? -When camera is focused at this distance, DOF extends from ½ hyperfocal distance to infinity (∞).

8. Depth of Focus ≠ Depth of Field • Depth of Focus IS… -Tolerance in the accuracy of the seating of the lens -The distance on either side of the focal plane where the film or CCD can be seated and still record an acceptably sharp image

9. Perspective • Is dependent on ONE factor: CAMERA-TO-SUBJECT DISTANCE!

10. The Lens and Perception • Define “Size Constancy” -A perceptual distortion that causes a mismatch between how we see an image and how a lens records it (I.e., optical illusions-created in the mind, not the eye/lens) • Why is this important? -May lead to discrepancies between how we perceive something and how the lens actually records it on film.

11. Shutter Speed, Aperture and Film Speed • Shutter Speed is measured by… - Fractions of a second. - 4 = ¼, 8 = ⅛, etc., so bigger #’s = SHORTER amount of time. • The size of the Aperture is measured in… - The size of the aperture is measured in F-STOPS. - The larger the f-stop #, the smaller the aperture. - F-stop = focal length/lens diameter • Common (ASA) film speeds include 50, 100, 200 ,400, etc. What does this doubling mean? -The doubling indicates that the film needs half as much exposure time, or is TWICE as fast.

12. Shutter Speed, Aperture and Film Speed (summary): • Shutter speed: Each # increase denotes… - A halving of the time the shutter is open • Aperture: Each f-stop increase denotes… - A halving of the diameter of the aperture • Film speed: Each increase in ASA denotes… -A halving of required exposure time for a given subject

13. Visual Design:Name the SEVEN VISUAL ELEMENTS: 1.) Space 2.) Line 3.) Shape 4.) Tone 5.) Colour 6.) Movement 7.) Rhythm

14. Visual Design: Space • Open Vs. Closed Space: -Closed space… …leaves NO room for interpretation: all the information you need is included in the frame. -Open Space… …DOES leave room for interpretation; for example, when a character is facing/reaching off screen, we don’t know what they’re reaching for.

15. Visual Design: LineName the EMOTIONAL QUALITIES of each type. • Horizontal -Associated with stability, balance, restfulness/serenity. • Vertical -Associated with power, strength. • Diagonal -Associated with confusion, chaos, internal struggles, tension, instability/imbalance.

16. Visual Design: Tone • Define TONE. - The value (light/dark) of objects in the shot. - I.e., contrast vs. affinity. • What are the THREE ways to control TONE? 1. Art Direction (reflective) 2. Lighting (incident) 3. Exposure (less selective) • What is coincidence/non-coincidence? -Value range reveals the subject of the shot. -Value range (partially) obscures the subject.

17. Visual Design: ColourWhat are the THREE attributes of COLOUR? 1.) Hue- -red, orange, yellow, green, cyan, blue, violet 2.) Brightness- -value/tonal range of colours, achieved by adding black or white 3.) Saturation- -saturation is the purity of the hue (more or less grey) -yellow desaturates to the lightest grey, while violet desaturates to the darkest grey.

18. Visual Design: Movement • Name the 2-DIMENSIONAL camera movements. -pan, tilt, zoom • Name the 3-DIMENSIONAL camera movements. -dolly/track, boom, crane *Define continuum of movement within the shot.

19. Visual Design: Rhythm • How is visual rhythm created? -Strategic use of stationary/moving objects and editing. • Define Alternation. -change • Define Repetition (of an alternation). • Define Tempo (of the repetition of the alternation).

20. Graphing Visual Structure • Contrast vs. Affinity • What do a progression, a constant and contrast/affinity look like as graphs? -Progression=SLOPING line -Constant=STRAIGHT line -Contrast/Affinity=sudden SPIKE

21. Visual Structure • Remember the Rule of Thirds • Define “Headroom” -Compositional space (negative space) above subject’s head. • Define “Eye-room” -Compositional space given in the direction the subject is looking (horror movie vs. other) • What are the common ASPECT RATIOS? -TV (standard def.): 4:3 -HDTV: 16:9 -Movie Theatre: 1:85:1; 2:39:1

22. The Shot • What are the THREE BASIC SHOTS? 1.) Long Shot (LS) 2.) Medium Shot (MS) 3.) Close-up (CU)

23. ECU MCU/”Two T’s” “Cowboy” “Head to toe” Tight shots/close shots Wide/Master/Est. shots Extreme close-up (less than whole face) From mid-chest up From just above the knee (MLS)- shows belt buckle Full-body shot/full shot A.k.a. Close-Up (CU) A.k.a. Long Shot (LS) The Shot: Hybrids/Hollywood Slang

24. The Shot: Angles • Define High Angle. -Camera placed ABOVE subject. • Define Low Angle. -Camera placed BELOW subject. • Define Canted. -Camera tilted laterally.

25. The Shot: Coverage • Define Master Shot (MS/LS/Est.) • Define Over the Shoulder (OS) • Define “Cutaways” -a shot to which the editor can cut in order to show an action or solve an editing problem. • Reaction shots • Inserts -Similar to Reaction shots; an insert is a shot of part of a scene as filmed from a different angle and/or focal length from the master shot. Inserts cover action already covered in the master shot, but emphasize a different aspect of that action due to the different framing. An insert is different from a cutaway in that the cutaway is of action not covered in the master shot.

26. Screen Grammar: What is Rabiger’s Approach? • Film works across cultures because it emulates human thought/the way our minds work.

27. Brief Shots Held Shots Close Shots Wide Shots Cursory glances used to orient ourselves Long looks in which we indulge Reproduce sensation of taking a detailed, focused look at something Emulates the way we look at things that are large, busy or distant Screen Grammar:According to Rabiger, what parallels are there in nature for…

28. Screen Grammar: Rabiger • According to Rabiger, what motivates a moving-camera shot in real life? -subject motivated (following target/moving object) -search motivated (looking for a person/object) -boredom motivated: reproduces natural tendency for wandering eye/attention • What are the THREE phases of a Moving-Camera Shot? 1. Starting Composition 2. Movement 3. Ending Composition

29. Screen Grammar:Master Scene Technique • What is the “classic pattern” ? MS > LS > Singles/OS > CU > Cutaways/Inserts • Define “Master Scene Technique” Approach in which director stages/shoots scene pretty much as it would be done in a theatre; all or part of scene is filmed in MS (a.k.a. est. shot), in which all/most of it’s elements are presented together. • What are some practical issues that arise? -How best to film CU’s; shooting out of sequence; who to cover first; off-camera dialogue

30. Screen Grammar:Shot/Reverse-Shot Technique • Define Shot/Reverse-Shot Technique. -Involves 2 camera set-ups: 1 for person A, 1 for person B. Cut together creates a simple, back-and-forth exchange (good for conversations).

31. 180 Degree Rule (the “line”/”axis”) • Can a scene have multiple/changing lines? -Yes, if there are multiple characters or moving characters. • The Rule requires constant awareness of the actors’ ____?____ -eye-lines (lines of sight- to left or right?) • Crossing the line intentionally is called a… -Jump Cut • Multiple characters = multiple… -”lines”

32. Screen Direction • Maintain screen direction on entrances and exits when scenes are close together _________ and __________. -Geographically and temporally. • What two types of movement can change screen direction within a shot? -Camera movement -Object movement

33. Directorial Communication Tools:Name all FOUR. 1.) Shotlists 2.) Overheads 3.) Lined Script 4.) Storyboards

34. Screenwriting • Know formatting. • What is the fatal flaw of screenwriting? -Passivity. • What kind of descriptions should/should not be included? -Script should include only what can be seen/heard; AVOID describing inner thoughts/emotions. • What is the Vonnegut Formula for a story? - ? ! .

35. Script Analysis • According to Weston, what is the FIRST step? -Cross out all screen directions- those are the director’s job! • Next? -Read the script allowed and compile first impressions. • What are “The Immutables” ? -Facts and Images which are implicitly stated and thus not subject to interpretation. • Next? -Imaginative choices- interpretation, including motivation (what’s at stake?) and choosing specific objectives and actions for each scene and each _______ within the scene. • A story can be divided up into major ______. Likewise, a scene can be divided into smaller _______. -events; beats.

36. Film/Video Interface • Define the two perceptual phenomena that may explain perception of motion. 1.) Persistence of Vision: -an optical/perceptual phenomenon that prevents us from seeing the dark space between the film frames by causing “flicker fusion” 2.) Phi Phenomenon: -also known at the “stroboscopic effect.” Creates apparent movement from frame to frame.

37. Exposure time and Shutter Angle Formula Exp. Time (Shttr Speed) = (1/Speed in FPS) X (angl of Shttr Opening/360) (MEMORIZE)

38. Overcranking/Undercranking • Define overcranking. -To shoot at more than 48 frames per second (doing 72 slows it WAY down) - makes SLOW motion when played at 24 fps • Define undercranking. -To shoot at 12 fps - makes FAST motion when played at 24 fps

39. Calculating Film Lengths • How many feet per minute for 35mm? 90ft / minute • How many feet per minute for 16mm? 36ft / minute

40. What are the layers in a piece of film? • Blue Sensitive Emulsion } • Yellow Dye } *** • Green Sensitive Emulsion }In black & white • Magenta Dye }white film, only • Red-Sensitive Emulsion } ONE emulsion • Cyan Dye } layer. • Antihalation Layer • Base

41. When shooting Tungsten(indoor) balanced film outdoors, use… This filter cuts ____ stops of light. When shooting daylight balanced film in a Tungsten(indoor) situation, use… This filter cuts ____ stops of light. An amber filter (an 85) 2/3 of a stop A blue filter (an 80a) 2 & 2/3 stops Colour Temperature

42. Keeping Track of Film • What is the difference between EDGE NUMBERS/KEY NUMBERS and KEYCODE? -Edge/Key NUMBERS= #’s photographically printed between sprockets on raw film stocks. -KeyCODE= (a sort of barCODE); electronically readable version of edge numbers, used during telecineing.

43. Video Controls • Exposure (f stops)• Exposure Index (light sensitivity)• Depth of field• Colour balance (white balance)

44. NTSC PAL/SECAM HDTV U.S. standard for TV: 2 interlaced frames, 29.97(~30)fps, 525 lines European standard: 25fps (50 fields), 625 interlaced lines 720 or 1080i –only 1080 is interlaced, progressive (lines placed sequentially) Video Standards:

45. Standard TV = -480 Pixels HDTV = -720 or 1080i Resolution

46. Define compression. • Discarding of redundant digital information/data in order to facilitate more efficient storage/recall of video footage (employed heavily with mini-DV format).

47. Colour Space • Refers to sampling rates for luminance and colour. Luminance:Red:Blue 4 : 1 : 1 = DV ^Higher # = better.

48. Drop Frame Time-code = ? • Drop frame timecode: drops average of 1.8 frame numbers (not frames!) per minute to account for fact that video is running at 29.97, not 30 frames per second. • Drops the ;00 and ;01 every minute except for the tenth minute. • Non-drop-frame timecode does not drop those frame numbers

49. Maintaining Continuity: • According to lecture, what is the MOST IMPORTANT part of continuity shooting? -Overlapping action!

50. Eye light Set light Kicker Accent Light Practicals often mounted near or on the camera. Puts a sparkle in the actor's eye Illuminates the furniture and walls similar to backlight, though traditionally lower and on the opposite side of the key glint of a knife, glow of a wine bottle light sources that are part of the scene Lighting