The only yellow filter you’ll ever need. Discover how much more detail is "exposed" with this unique filter. This filter has a unique curved design that has renders more ridge detail when taking photographs with the Blue Lasers (315-460nm) with an optical density of 5+. and other laser alternate light sources in the 315nm-460nm range. This Long Pass Filter blocks outside laser/ALS light and passes longer wavelengths emitted from trace evidence samples to capture images with more detail using a suitable camera. Made of polycarbonate. Other sizes available. The Curve filter allows you to compensate for Gaussian roll-off of non-oblique light (not heading directly into the lens axis). Made of polycarbonate. 77mm