Photography/Visual Imaging

Why take pictures or capture othe visual images during an investigation?

• To document EB sources, help illustrate what happened, and preserve data.

• People tend to focus on what attracts their attention in a scene; photos record everything in sight, providing visual and durable documentation that will not change.

• Photos help make mental movies by showing the setting or "stage" on which incident occurred.

Preplan

• Prepare for photo taking by practicing with the camera you will use before you need it. Or,
  
• Arrange for local photographers who will know what is needed beforehand.
  
• Give someone authority to hire, direct photographers.
  
• Make sure everyone knows investigation policy; too many photos always better than not enough.

Rules for investigation photography.

Use film camera for "evidence" shots. Digital camera or video OK for snapshots for quick distribution, sharing info among investigators, other timely investigative tasks, but much more prone to tampering or modification.

Rule 1. Photos should provide an accurate permanent record of scene:

You are not seeking artistic/sensational prize winning creation; scene includes not only accident, but often backgrounds and bystanders, especially in fires

Rule 2. Make sure photos are printed faithfully.

Not reversed, cropped, off-color. If more detail is needed, changing contrast may help. Use color referent if color accuracy or color differences or color changes over time are important.

Rule 3. Assure correct perspectives.

Use appropriate focal length, lens angle. Grids may work on flat surfaces. Have horizontal lines to aid perspectives. Shoot from different perspectives.

Rule 4. Use camera settings needed for situation.

Use auto exposure in situations with mid-range lighting. To cope with lighting differences, take with different light sources, angles; check shutter speed versus film speed, use meters, extra lighting, etc. with film camera. Don't use flash near unknown or flammable vapors.

Rule 5. Provide accurate size reference.

Use people, coins, ruler, etc. as references. Sometimes OK to put a hand in picture.

Rule 6. Use color for maximum information content.

Record data in colors. Use color bar if exact color is important, as with fires, charts, to help developers, investigators.

OSHA has nice form. Documentation should include:

Rule 8. Show enough of the scene to provide good orientation.

Go from long shots to close-ups of detail. Cover from different angles. Aerial invaluable for outside accidents, fires, explosions. Aerial may be available as baseline for before/after information. (Check US Geological service, or satellite photo sources.)

Rule 9. Film and digital memory is relatively cheap.

Don't skimp and have to send someone back a second time ( it may be gone). You may not have to print everything by the time you understand what happened. On the other hand, look at shots to see what you might be missing.

Rule 10. Don't overlook other options to capture data visually like

multispectral: like landsat shots.

stereo: easy - just take two shots of same subject from places 2-3 feet apart.

thermal; scanners for fires, including digital thermal scanners.

motion pictures: including high speed simulations.

video tapes, especially for documenting walkthroughs, simulations.

To sum up:

1. Think of visual records as documentation of incident witness plates.
2. Document as much as you can before it changes.
3. Better too much than too little.
4. Watch for tricks and distortions with photography. Examples:
   Defendant: make it look as good as you can (colorful, bright, full scope, etc.).
   Plaintiff: make it look as bad as you can (dull, dark, drab).