Forensic Photography & Imaging
Forensic Photography & Imaging tests the IAI CFPH candidate on the technical and documentary controls that make a photograph evidentiary: exposure and optics, lighting, scale and perspective, specialized imaging, and digital integrity. The exam favors practical settings and a defensible workflow over artistic effect.
Exposure and optics
Use the exposure triangle deliberately: aperture controls depth of field, shutter controls motion and camera shake, ISO controls amplification and noise. For scene and evidence work, use a tripod, a mid-aperture (commonly f/8–f/11) and the lowest ISO that permits adequate flash exposure. Expose to the histogram, avoiding clipped highlights, and bracket difficult scenes. Capture RAW, retain the original file, and record camera, lens, flash and settings in a photographic log.
Documentation sequence and scale
Photograph overall, midrange and close-up, moving from the general to the specific before collection. Every evidence close-up should include a scale. The ABFO No. 2 is an L-shaped photomacrographic scale with millimeter graduations and gray/white/black reference patches; place it in the same plane as the subject and do not obscure the evidence. Keep the camera back parallel to the subject plane, fill the frame, and use a normal or macro lens to limit perspective distortion.
Lighting and specialized imaging
Flash is the workhorse: direct, bounced or diffused. Use oblique/raking light to show texture and indentation; use axial or coaxial light for reflective surfaces. UV and IR require camera conversion or specialized illumination and filters, plus documented exposure. White balance with a gray card when color is evidentiary.
Worked example
A bloodstain on a wall: overall room shot with case card; midrange wall view; close-up of the pattern with an ABFO scale in the wall plane. Camera on tripod, 60 mm macro, f/11, ISO 200, manual flash; bracket and check histogram. The reasoning: the tripod removes shake, f/11 gives the pattern and scale adequate depth of field, the in-plane scale allows measurement, the frame is filled, and RAW is retained.
Traps
Scale tilted out of plane; flash hotspot; motion blur from handholding; perspective convergence from standing too close; JPEG originals; editing the only copy; forgetting overall shots; using a scale that covers the pattern; mismatched color balance.