Digital Infrared Photography
Norman Marin, Jeffrey Buszka · Routledge eBooks · 2013
Our eyes can only perceive the visible light portion of the electromagnetic spectrum. However digital cameras with silicon-based sensors are sensitive to infrared radiation. The effectiveness of forensic infrared photography lies in the ability to create contrast on difficult to manage or dark backgrounds. Examples of this would be the visualization of gunshot residue or bloodstains on black-colored fabrics. Objects that appear similar in color with the unaided eye may appear completely different when photographed in infrared. Photography using infrared techniques typically requires the use of a full-spectrum camera coupled with infrared transmitting filters.