Black Light Test

[Service Tech 0]

So last night I decided to test the UV dubbing that I have been acquiring lately with a black light. I found that only 1 of the dubbing packages that was marked UV actually glowed with the black light on. Now that brings me to a question, am I still not able to see some of the UV wavelengths with the black light or do you suppose that the UV designation is just a selling point of the materials? I did find that materials marked fluorescent glowed nicely.

[SilverCreek 0]

So last night I decided to test the UV dubbing that I have been acquiring lately with a black light. I found that only 1 of the dubbing packages that was marked UV actually glowed with the black light on. Now that brings me to a question, am I still not able to see some of the UV wavelengths with the black light or do you suppose that the UV designation is just a selling point of the materials? I did find that materials marked fluorescent glowed nicely.

 

You are testing for UV fluorescence and not UV reflectance! UV dubbing reflects UV and does not fluoresce.

 

Since UV is invisible to you so if UV dubbing reflects UV, you won't see it.

 

http://en.wikipedia.org/wiki/Fluorescence

[Piker20 0]

Silver creek hits the spot. some of the 'UV' products are fluorescent but not actually UV reflective. It is doubtful they are even UV fluroescent. Its a marketing gimmick you could say.

True UV reflective products as Silver says will not show to the naked eye even under black light but the UV fluorescent ones should glow, like JC eyes

[Service Tech 0]

I guess I should read the book "The New Scientific Angling - Trout and Ultraviolet Vision" as PlanetTrout has mentioned a time or two. I did some more information search after Silver Creeks reply and have a better understanding.

[Piker20 0]

There has been a lot in UK magazines over the last few years regarding which is better for us in materials. A fluorescent or a reflective one. JC eyes have been used for a long long time and black light has shown them to be very fluoro. The materials that don't show as fluoro we can only hope are reflective cause we will never see them to be sure!

I'll be interested to hear how you find it goes when fishing; the fly tied with material that glowed under black light and the fly tied with, what you hope is UV reflective material?

My money is on the glowing one to our eyes.

[flytire 0]

It is not up to our eyes to judge the uv products as the human eye supposedly doesn't see uv light. It up to the fish to decide

[lykos33 0]

I thought the "UV" designation only meant the product needed UV light to activate the product, not that it gave off or reflected UV light?

Murray

[JSzymczyk 0]

Murray, you might be thinking of UV cured acrylics (epoxy substitutes) which have been all the rage lately.

[sandflyx 0]

these are steel-seal dubbing for stellhead flys. 1 is under blacklight, 2 is same with a few more colors. 3 and 4 are under normal light. even some of these don't all glow like we wish they would, still have great colors in water.

[flytire 0]

Time to read the book

 

"The New Scientific Angling - Trout and Ultraviolet Vision"

[mikechell 0]

Black lights are very low energy source of ultra-violet light. And they are only operating in the UV-A range. Just because something doesn't glow under a black light does not mean it isn't reactive to UV light. But it is a good indicator of whether something is easily seen with low levels of UV-A ... which is what you'll have underwater ... very low energy level UV light. I'd guess that the material that doesn't glow with the black light, won't appear any different underwater.

[SilverCreek 0]

Here are a few URLs on UV materials and UV vision.

 

http://oregonflyfishingblog.com/2011/02/09/ultra-violet-fly-tying-materials-catch-fish-qa-with-author-reed-curry/

 

http://spiritriver.net/uv

 

http://turningoversmallstones.blogspot.com/2009/09/ultraviolet-vision-and-trout.html

 

I had a discussion with Reed Curry, the author of The New Scientific Angling: Trout and Ultraviolet Vision, about UV vision on:

 

http://www.theflyfishingforum.com/forums/coldwater-fly-fishing/301945-does-blue-excite-trout.html

 

There are differing opinions about whether adult trout can see UV. Reed presents some studies that show some UV cones persist into adulthood but it is unclear to me whether they are at the same density as in the parr. So it is unclear to me whether they see UV as well as young parr trout see UV. Secondly, these UV cones are on the dorsal retina (the upper surface) which sees the lower 1/2 of the visual field.

 

Other writings state that adult trout do not see UV.

 

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

 

http://www.sexyloops.com/articles/whatsalmonidssee.shtml

 

Let us assume that adult rout can see UV. Since we cannot see UV ourselves, we cannot tell by looking at a natural what frequency (color) of UV the natural reflects. Similarly, we cannot tell by looking at a dubbing or other tying material what UV color it reflects. Therefore there is no practical way to match the UV reflectance of a tying material with the UV appearance of the natural. For me, that is the weakness of any argument that says we should "match" UV, when there is no practical way to "match UV.

 

If we cannot match the actual UV reflectivity of a natural, and we use UV reflective materials; I believe it is like adding some visual attractant like the flash material to a pattern to attract the attention of a trout.

 

UV fluorescence is something different. Since the higher energy UV penetrates more deeply into water, UV fluorescent material can make a pattern more visible to the trout. Fluorescence is different from phosphorescent materials that glow in the dark and must be activate by UV light.

 

So when we mention UV materials, there are three types - Reflective, Fluorescent, and Phosphorescent. I leave it up to you to decide what materials should be used and how they should be used.

[lykos33 0]

Murray, you might be thinking of UV cured acrylics (epoxy substitutes) which have been all the rage lately.

 

You're right . I totally missed the "dubbing" in the first post. In carpentry they say 'measure twice cut once', I guess when I read the forum I should 'read twice post once'...

Murray

[whatfly 0]

So last night I decided to test the UV dubbing that I have been acquiring lately with a black light. I found that only 1 of the dubbing packages that was marked UV actually glowed with the black light on. Now that brings me to a question, am I still not able to see some of the UV wavelengths with the black light or do you suppose that the UV designation is just a selling point of the materials? I did find that materials marked fluorescent glowed nicely.

 

You are testing for UV fluorescence and not UV reflectance! UV dubbing reflects UV and does not fluoresce.

 

Since UV is invisible to you so if UV dubbing reflects UV, you won't see it.

 

http://en.wikipedia.org/wiki/Fluorescence

Which begs the question, is there relationship between fluorescence and reflectance, or is this rush to UV materials just so much bupkis? One assumes that their may be but not necessarily a proportional relationship between the two characteristics, which makes all this UV marketing dubious at best...

[SilverCreek 0]

So last night I decided to test the UV dubbing that I have been acquiring lately with a black light. I found that only 1 of the dubbing packages that was marked UV actually glowed with the black light on. Now that brings me to a question, am I still not able to see some of the UV wavelengths with the black light or do you suppose that the UV designation is just a selling point of the materials? I did find that materials marked fluorescent glowed nicely.

 

You are testing for UV fluorescence and not UV reflectance! UV dubbing reflects UV and does not fluoresce.

 

Since UV is invisible to you so if UV dubbing reflects UV, you won't see it.

 

http://en.wikipedia.org/wiki/Fluorescence

Which begs the question, is there relationship between fluorescence and reflectance, or is this rush to UV materials just so much bupkis? One assumes that their may be but not necessarily a proportional relationship between the two characteristics, which makes all this UV marketing dubious at best...

 

To my knowledge, reflectance and fluorescence are two independent properties.

 

Fluorescence is the property of a material to absorb energy of a certain wavelength (color) and emit in as a different color. The emitted color has a longer wavelength and lower energy than the energy absorbed. That is why the higher energy, higher frequency UV light is absorbed and emitted as a lower visible wavelength.

 

Why is the wavelength and energy lower? Because in all energy conversions, some energy is lost, and so a photon of one energy that is absorbed must be emitted at a lower energy photon. This means that if there are materials that absorb red photons and emit infra-red photons, we cannot see the fluorescence.

 

Reflectance is color and UV color reflectance is a color not visible to us. We do not know how animals that can see into the UV actually perceive the color. What I mean by that is, what is the color spectrum of someone or something that can see into the UV? How do things look to them?

 

We have a form of color blindness, we are color blind to UV. It is not just that the color "UV" is missing our color spectrum. The spectrum itself look different compared to an animal that can see UV.

 

Our "normal" color spectrum is that of an animal that is colorblind to UV. We can "imagine" the difference by comparing our "normal" spectrum with someone who is color blind to one of the colors (blue, green, red) that we can see.

 

Check the chart below. Note the normal vision at the top and the various types of color vision below. A color does not just drop out, the entire spectrum is different!

 

 

 

The difference is more apparent with a side to side comparison:

 

Deuteranopia = no Green receptors

Protopanopia = no Red receptors

Trinanopia = no Blue recpetors

 

 

Then there are combinations of the color blindness:

 

 

 

We can then see by the examples of colorblindness above that a person that is colorblind would have a hard time matching the color of dubbing or tying materials to a natural. Similarly, we are colorblind to UV so how can we match the "color" of a natural to dubbing or tying material when we do not see UV. Our color wheel does not match the color wheel of an anima that sees UV. If an adult trout sees UV, I think we cannot just toss some UV material into a pattern and think it matches what the fish perceives.