Coaxial Light Guide & Illuminator

Description

Designed to aid the investigator in the visualization and photography of impression evidence on all reflective surfaces (such as glass, polished metal & plastics, varished wood, glossy paper) using standard photographic equipment and techniques. The device is nondestructive to any evidence tested. It is a first step in the examination of evidence which will not compromise further testing procedures.

The coaxial path followed by the light results in a uniform bright field reflection directed along the lens axis and onto the imaging plane. The only interruption of the bright field is the ridge detail present on the surface of the mirror. Since the ridge detail prevents a direct reflection of the coaxial light onto the film, it appears dark to the camera. The resulting image is that of a dark fingerprint on a light background. The use of coaxial lighting allows positioning the camera directly above the mirror, minimizing offset ridge reflections. The result is similar to the silver plates used with iodine fuming when examining cadavers for fingerprints.