Learning to use the UV Light
Deer and other game can easily see Optical Brighteners. We don't see them because we have a UV filter in the lens of our eye to protect it from sun damage. We are much more sensitive to longer wavelength colors, but in a dark room with a proper UV light source, we too can see the UV Glow.
WARNING: Do not look directly at any UV Light source. They are more powerful than they appear and can damage your eyes.
The ideal light source to reveal optical brighteners is a 350 BLB fluorescent black light. These are available in sizes from 6" to 48". A 6" battery powered model is available from Atsko Inc. We also offer custom manufactured LED lights. These are very compact, and will reveal the presence of brighteners. Incandescent (screw-in) black lights will not work.
With the right light, a darkened room, and samples of white paper with and without optical brighteners, you can learn to detect the same glow that animals see. Bright paper is everywhere, any sheet of copy paper will do. Originals of this document are printed on paper with no UV Brighteners, so it can be used in the test. Paper plates and newsprint paper usually contain very little if any brightener. Arrange the two papers overlapping each other. They both appear white in ordinary light. Now turn off the room light and cut on the black light. Notice the copy paper has a bright blue glow that is not seen on the unbrightened paper. The bright blue glow indicates the presence of OPTICAL BRIGHTENERS.
Move the UV light source closer to and further from the white targets. Notice that when you get very close, even the dark paper begins to look blue. This is a "false" glow caused by the little bit of blue light that is escaping from the black light. Almost all UV lights have some blue content and it tends to confuse our test. You can minimize the confusion by keeping the light far enough away so that the unbright paper does not glow. Remember this distance. It should be the minimum distance when checking laundry detergent, camouflage, and blaze orange fabrics. With a fluorescent 350 BLB this distance will be about one tube length.
If you have some U-V-Killer, agitate it and apply some to both papers. WOW!!! The copy paper darkens dramatically, but it makes no difference on the other.
U-V-Killer works by absorbing the Ultraviolet energy before it reaches the brighteners. The energy absorbed by U-V-Killer is converted to longer wavelengths (reds) which deer don't see. Without U-V-Killer, the UV energy is converted to bright blue, right at the peak of the deer's vision. They see the blue glow at least 1000 times as bright as we do.
After testing and treating all your camo and blaze orange, tell your friends. Unlike scents, which are less effective when used by more hunters, the use of U-V-Killer does not provide a clue to help deer identify hunters. It lets your camo pattern work as it was designed to. In good light, you will be a pattern of shades of yellow in a field of shades of yellow, instead of a bright glowing blue flag. In dawn, dusk, and shadows you will be a pattern of grays instead of a neon sign. You will see more animals. The military specifies "no optical brighteners" for all their camo, and they are mostly hiding from humans. The glow is 1000 times as important when hiding from animals. They see the blue glow brighter than humans see blaze orange.