Photography and optical enhancement of physical evidence

Photographic and optical enhancement of physical evidence is an important function in criminalistics and provides nondestructive methods of improving the visualization of forensic evidence. The key concepts and techniques involving optical, photographic, and digital imaging techniques are examined in this section. Essential foundation principle required in quality forensic photography such as maintaining the dimensional integrity of evidence and the representation of scale are discussed. Attributes for optical enhancement including the relationship between the spectral distribution of the light source, the spectral properties of the specimen, and spectral sensitivity of the recording media are explained and provide a theoretical basis. Optical enhancement techniques such as absorption, reflection, transmission, and photoluminescence modes are discussed with samples illustrating those optical effects. Digital imaging enhancement techniques to increase the contrast and the modification of color using Adobe Photoshop™ are explained