Archaeological Photography Workshop Field Archaeology ARCH1003

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Archaeological Photography WorkshopField
Archaeology ARCH1003
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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?

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Single Lens Reflex (SLR) Camera Features

• ISO setting
• Shutter release
• Frame counter
• Focal plane shutter
• Remote release socket
• Film Window
• Mirror
• Prism

• Lens
• Lens aperture
• Focusing ring
• Auto Advance
• Aperture or AV value
• Hot shoe
• Shutter speed or TV (Time Value)

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Light

• Light is focussed through a lens by refraction
  (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)

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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

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Relationship Between Aperture and Light
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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)

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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)

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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

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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)

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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

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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

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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

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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

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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

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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

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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

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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

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Photo Illustration
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Photo Illustration
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Aerial Site OverviewPhoto David Webb, UK
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Critique Photograph
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Critique Photograph
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Critique Photograph
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Critique Photograph
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Scale
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Scale Position/Use of Negative
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Human Scale/Site Context
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Scale/Use of Negative/Cleaning
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Direct Sunlight/Contrast
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Diffuse Light
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Overcast Lighting/Scale/Use of Negative
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Background Placement, Scale, Glass in Sunlight
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Artefact Use Visualization
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Finger as Scale
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Scale Size/Placement
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Scale Placement
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IFRAO scale AURA, PO BOX 216, Caufield South VIC
3162auraweb_at_hotmail.com
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Rock ArtIFRAO scale
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Studio Lighting
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Studio Lighting