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Archaeological Photography Workshop Field Archaeology ARCH1003. Archaeological Photography Objectives. Photo Documentation (Hester 1997) A comprehensive and technical record of an investigation from beginning to end

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Archaeological photography workshop field archaeology arch1003

Archaeological Photography WorkshopField Archaeology ARCH1003


Archaeological photography objectives
Archaeological Photography Objectives

Photo Documentation (Hester 1997)

A comprehensive and technical record of an investigation from beginning to end

Excavation, process of recovering artefacts, sequences, units and profiles, survey finds. It is a historical record

Ethical responsibility of archaeologist to visually record an irreversible process such as excavation or survey. Subsequent analysis or re-analysis of your work in future

Photo Illustration (Hester 1997)

To provide images for publication or presentation

What are you trying to communicate to the public or in the journal?

Why photograph and illustrate?


Single lens reflex slr camera features

Lens

Lens aperture

Focusing ring

Auto Advance

Aperture or AV value

Hot shoe

Shutter speed or TV (Time Value)

ISO setting

Shutter release

Frame counter

Focal plane shutter

Remote release socket

Film Window

Mirror

Prism

Single Lens Reflex (SLR) Camera Features


Light
Light

Light is focussed through a lens byrefraction (bending of light rays) to form an image behind the lens

To produce a photograph we need:

A light source

An object such as a mirror to reflect the light

A light sensitive medium to record the reflected light (film/digital sensor)

Colour temperature (degrees Kelvin)


Aperture value
Aperture Value

Aperture = f/stop = AV (Pentax camera)

Size of the aperture opening in the lens

A large number (F22) is a small aperture

A small number (F2.8) is a large aperture

To stop down is to reduce the aperture

The f number derives from dividing the focal length (mm) of the lens by the diameter of the aperture



Time value shutter speed
Time Value/Shutter Speed

Time Value = shutter speed = TV (Pentax camera)

Length of time the camera shutter opens to expose the film/sensor to the light coming through the lens

1/8 second or slow shutter speed (requires tripod to avoid camera shake)

1/4000 or fast shutter speed (captures water splashing)


Exposure
Exposure

Exposure is the total amount of light reaching the film calculated from a combination of aperture value (AV) and time value (TV)

Reducing the AV value (or f-stop) from f16 to f22 necessitates doubling the exposure time or TV (time value) for the same exposure result

1/250 second at f22 will give the same exposure result as 1/125 second at f16 (TV reduced but aperture opened up)


Depth of field
Depth of Field

Depth of field is the zone extending in front of and behind the focussed distance within which points will appear to be sharp

The smaller the aperture (AV 22) increases the depth of field

The larger the aperture (AV 5.6) decreases the depth of field

Shorter focal length (wide-angle 28mm) increases depth of field

Longer focal length (telephoto 300mm) decreases depth of field


Focal length
Focal Length

Light travels in parallel beams and reaches the lens

The distance between the lens and the point at which such light is focussed is the focal length of the lens

It is always expressed in millimetres

An object the same distance away from a long focal lens will give a larger image than one of short focal length

Standard focal length is 50mm for 35mm camera (negative is 35mm x 24mm)


Angle of view
Angle of View

The angle of view for the human eye is around 45 degrees

Angle of view is the amount of the scene in front of camera taken in by the lens.

A fish eye lens (18mm focal length) will provide 180 degrees angle of view

A telephoto lens (1200mm focal length) will provide 2 degrees

Note: A longer focal length (300mm lens) will decrease the depth of field


Film speed
Film speed

ISO film speed is the films sensitivity to light rating

The more sensitive the film, the higher the ISO number and the less light required

ISO 6 is a slow, fine grained film and requires a tripod

800 or 1600 ISO is a fast film (newer films not so grainy, used with/without flash)

TMax 3200 can be used with available light at night


Perspective
Perspective

The apparent distance in the relative sizes of near and far objects

A function of the distance away of the camera

Wide angle distortion 28 to 35mm may steepen the perspective of your trench or structure leading to convergence of lines and aberrations at edge of negative

Standard focal length lens (50mm) or higher will give normal perspective

Telephoto lens (above 50mm) may flatten perspective


Metering
Metering

Current Single Lens Reflex (SLRs) cameras have built in metering

Correct Exposure (Pentax) is when the green light is half-way and is changed by adjusting AV/TV values

If positive = overexposed

If negative = underexposed

Note: internal meter reads whole scene not just object unless that fills the frame

Incident, reflective, spot metering, grey cards


Camera handling and care
Camera Handling and Care

Dirt, water, dust, sun can damage cameras and/or precious exposed film

Use bag or waterproof case (e.g. Pelican) for rainy days

Lens tissue for clearer picture. Check the lens!

filters will help protect the lens

Do not over tighten the tripod screw

Batteries may leak if for a long time in the camera


Field equipment

Scale (range pole and/or centimetre scales)

Additional cameras (black and white, slide and/or colour print, digital)

Photographic proforma or notebook/register

North arrow

Tripod and remote cable release

Flash/Supplementary Lighting

Film! cards/laptop/burner

Batteries

Filters

Special requirements for digital cameras

Camera hood and waterproof case

Reflectors

Lens cleaning material

Special lenses

Field Equipment


General principles of archaeological photography

Technical Photograph descriptive and realistic

Control the light

Use an appropriate scale

A scale should be in the same plane as the object

Viewpoint is critical. Fill the frame. Use macro lenses/function for small objects

Film/CD media is low cost, while project time is not Exposure is critical

Record on proforma/notebook (Never Later)

Record meaningful information

A changing landscape?

Detail, Geology, construction materials, flora,

Save images to digital archive at highest resolution possible and back up records

General Principles of Archaeological Photography


Overall site and aerial photographs
Overall Site and Aerial Photographs

The relationship between a site and surroundings is essential. Try to convey a sense of context or environment

Try to take an elevated photograph if possible (wall, ladder, tree, elevating machinery, box

Conventional aerial photographs - planes,

Low-level aerial photographs - booms, balloons, and kites




Aerial site overview photo david webb uk
Aerial Site OverviewPhoto: David Webb, UK


















Ifrao scale aura po box 216 caufield south vic 3162 auraweb@hotmail com
IFRAO scale AURA, PO BOX 216, Caufield South VIC 3162auraweb@hotmail.com


Rock art ifrao scale
Rock ArtIFRAO scale