Advanced Illumination Edge-lit Collimated LED Backlights provide highly uniform, collimated illumination with low heat output. The low divergence angle of the light rays make them ideal for use with telecentric imaging lenses. While the light rays exiting standard backlights have wide and diffuse angles, the light rays exiting these backlights are collimated at lower divergence angles for improved edge contrast in silhouetting applications such as web inspection and defect detection. While Telecentric Illuminators with highly collimated light rays are ideal high precision measurement and gauging applications, they can be large and cost restrictive. Collimated Backlights can be a great option for space-limited measurement applications.