Does UV really work?

[Silver Creek]

I apologize if this has already been discussed. I am curious about the "UV" fly tying materials I see advertised in the fishing catalogs. What is your experience? Do you think using UV-treated fur, feathers, etc., really make any difference in fish taking your flies?
Thanks for your opinions.
G.H.

This subject has been discussed before on this forum and others:

http://www.flyanglersonline.com/bb/s...213#post491213

http://www.theflyfishingforum.com/fo...d-myths-2.html

http://www.theflyfishingforum.com/fo...als-trout.html

http://www.flytyingforum.com/index.p...7&#entry524267


There are three types of UV materials. There are materials that convert invisible (to humans) UV light into visible light. These materials absorb the UV light and then re-emit it as visible light. If the visible light is re-emitted immediately, this is fluorescence. If there is a delay in re-emission, this is phosphorescence.

Fluorescent and phosphorescent materials have been around for years, and are nothing new. But they are advertising themselves as "new". Some of the "new" materials have strands of UV fluorescent materials in the dubbing. Take a UV flashlight and shine it on packets of these "new" materials and some of the fibers will glow. The way they work is to convert UV into the visible spectrum and add to the amount of visible light coming from the fly. They work as visual attractants. Natural nymphs and pupa do NOT glow under UV light so these materials are NOT IMITATIVE.

The third type of materials reflect UV light. But we cannot see into the UV spectrum so we cannot see the UV reflectance. Some natural food items of trout reflect UV light. UV is an entire color palette so it is NOT a single color. So if we are to match a UV color of a food item, the fly tying material has to reflect that UV color and not another UV color. That makes matching UV color very difficult because we cannot see the UV color of the natural and we cannot see the UV color of the fly tying material. It is like a person that has red/green color blindness trying to match a red/green natural with dubbing with a mixture of red/green that he cannot see.

Secondly, for UV reflectance to be of value, the trout has to be able to see into the UV spectrum. Young trout do. There is disagreement whether adult trout do, and if they do, how much UV they can see. Reed Curry, who posts as Overmywaders, has written a book (The New Scientific Angling: Trout and Ultraviolet Vision) on UV vision and fly tying materials, and he believes that adult trout can see into the UV and that tying flies to match UV is important. He recommends some natural materials that reflect UV light.

Reed's book is here:

http://www.amazon.com/The-New-Scient.../dp/0984086307

Jason Randall has written a book (Trout Sense: A Fly Fisher's Guide to What Trout See, Hear, & Smell). Jason has the opposite opinion about the place of UVR in trout vision and feeding behavior. He also states that in his recent podcast.

You can access portions of Jason?s book here:

http://books.google.com/books?id=7SM...vision&f=false

Jason's book and podcast are here:

http://www.amazon.com/gp/product/B00NQCVTEK?btkr=1

http://www.askaboutflyfishing.com/sp...rout-sense.cfm

Additional writings state that adult trout do not see UV.

http://www.troutu.com/class/color_vision_trout_eyes

http://www.sexyloops.com/articles/wh...onidssee.shtml

So there is considerable controversy about UV vision in trout. Midcurrent has a general article about color and then two opposing article on matching UV color.

http://midcurrent.com/science/fish-e...-color-matter/

http://midcurrent.com/flies/not-vision-perception/

http://midcurrent.com/science/to-uv-or-not-to-uv/