A valuable technique for insuring accurate exposures, especially for scenes with deep shadows, is flash fill. In scenes illuminated by bright sunlight there will usually be dark shadow areas. Sometimes evidence is located in the shadows. Detail in the deep shadow areas may be lost when the exposure is based on the overall brightness of the scene. With the use of flash fill, the brightness level in the shadow areas can be raised to the overall brightness of the scene.
Many cameras with dedicated TTL (through-the-lens) flash systems can provide automatic flash fill. If you have a dedicated TTL flash system consult the equipment instruction manual for instructions on using flash fill in the camera's automatic exposure mode.
You can also use a camera and an electronic flash unit in manual modes for flash fill. First you must set the camera's shutter speed to the camera's flash synchronization speed (usually 1/60 or 1/125 second). Then use the camera's exposure meter to determine the correct f-stop for the shutter speed selected. Set that f-stop on your lens. With the flash on manual, find the flash-to-subject distance for the f-stop that was selected (the flash-to-subject distance for each f-stop is usually displayed in a chart on the back of the electronic flash). Position the flash unit at that distance from the shadow area and take the photograph.
You may wish to use a flash remote cord so you can have more flexibility in choosing the proper angle to direct the electronic flash into the shadows.
Flash Fill in Crime Scene and Evidence Photography Copyright: © 2014 by Steven Staggs. Copyright for this article is retained by the author, with publication rights granted to the Crime Scene Investigation Network. This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License which permits unrestricted noncommercial use, distribution, and reproduction, provided the original work is properly cited and not changed in any way. Based on a work at http://www.staggspublishing.com/CrimeScenePhotography.html.
The information presented in this article is from the book
Crime Scene and Evidence Photography, 2nd Edition © 2014 by Steven Staggs.
Crime Scene and Evidence Photography, 2nd Edition is designed for those responsible for photography at the crime scene and in the laboratory. It may be used by law enforcement officers, investigators, crime scene technicians, and forensic scientists. It contains instructions for photographing a variety of crime scenes and various types of evidence. It is a valuable reference tool when combined with training and experience. Crime Scene and Evidence Photography is also a helpful resource for students and others interested in entering into the field of crime scene investigation.
For the past 30 years Steven Staggs has been a forensic photography instructor and has trained more than 4,000 crime scene technicians and investigators for police and sheriff departments, district attorney offices, and federal agencies. He is also a guest speaker for investigator associations, appears as a crime scene investigation expert on Discovery Channel's Unsolved History, and provides consulting to law enforcement agencies.
Steve has extensive experience in crime scene photography and identification. He has testified in superior court concerning his crime scene, evidence, and autopsy photography and has handled high profile cases including a nationally publicized serial homicide case.
Steve is the author of the Crime Scene and Evidence Photographer's Guide, a field handbook for crime scene and evidence photography, which has sold over 40,000 copies and is in use by investigators in more than 2,500 law enforcement agencies.
Steve retired in 2004 after 32 years in law enforcement, but continues to teach forensic photography and crime scene investigations at a university in Southern California. He is the President of Crime Scene Resources, Inc. and Webmaster of the Crime Scene Investigator Network, the world's most popular Crime Scene Investigation and Forensic Science website (www.crime-scene-investigator.net).
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Article posted: September 26, 2104