UV or is it??

Discussion in 'Fly Tying' started by Jack Devlin, Aug 9, 2012.

  1. Jack Devlin

    Jack Devlin Active Member

    Joined:
    Oct 16, 2011
    Messages:
    1,267
    Likes Received:
    1,079
    Location:
    Western Washington, Puget Sound area
    View attachment 17554 View attachment 17553 View attachment 17553 View attachment 17554 With the popularity of UV materials now, are you sure you are actually getting what you are paying for? Today I purchased some clearly marked UV flash. When I put it under black light nothig showed up. I've encountered this on some other materials purchased recently and from different suppliers. So, from now on, I take my UV flashlight with me to the fly shop. After all, we are paying extra for the UV. Why not make sure it is there. Something to think about. I now understand that we cannot see UV, only florescence (I think).
     

    Attached Files:

  2. Jack Devlin

    Jack Devlin Active Member

    Joined:
    Oct 16, 2011
    Messages:
    1,267
    Likes Received:
    1,079
    Location:
    Western Washington, Puget Sound area
    DSC04396.jpg DSC04397.jpg

    This is what I thought UV should look like.
     
  3. Norm Frechette

    Norm Frechette Googlemeister

    Joined:
    Oct 16, 2004
    Messages:
    624
    Media:
    6
    Likes Received:
    96
    Location:
    Norwich, CT
    so how are they breeding uv into hackles?
     
  4. Jack Devlin

    Jack Devlin Active Member

    Joined:
    Oct 16, 2011
    Messages:
    1,267
    Likes Received:
    1,079
    Location:
    Western Washington, Puget Sound area
    I guess they just leave the chickens out in the sun all the time??:)
    I'm not sure how UV is added. I guess it is a chemical additive during the dyeing process eh?
    All I know is that some materials marked UV when put to the test under black light are not UV.
    Jack
     
  5. jwg

    jwg Active Member

    Joined:
    Aug 22, 2009
    Messages:
    609
    Likes Received:
    135
    Location:
    West Richland, WA
    I have always been a little puzzled by what the UV label meant.

    You have tested for whether the materials fluoresce under UV light, absorbing UV and giving off longer wavelength visible light that you can see.

    The other possible meaning of UV would be that fish can see UV light, which we cannot, and this helps them to identify food, and see through dim water. So this would be about UV light reflecting off an object and being seen by the fish.

    Your post prompted me to try to sort this out.

    This page from a materials supplier seems to indicate they mean reflectance of UV light:
    http://spiritriver.net/uv

    and this blog implies the same.
    http://oregonflyfishingblog.com/201...terials-catch-fish-qa-with-author-reed-curry/

    So I think the point of UV materials is they reflect the ambient UV light, and the fish can see this. There would be no way to tell if the claim were true in the store using our human eyes which cannot see if the UV light is reflected.

    Jay
     
  6. Jack Devlin

    Jack Devlin Active Member

    Joined:
    Oct 16, 2011
    Messages:
    1,267
    Likes Received:
    1,079
    Location:
    Western Washington, Puget Sound area
    If you read my initial post you will note that I say " So, from now on, I take my UV flashlight with me to the fly shop." The point was that just because a package says UV it may not be so. Sometimes, the UV label is the only thing which responds to a UV light source. In other words, let the buyer beware. If you have a UV light shine it around your tying bench and your materials. You might be surprised what "lights up" in response to the light.
    Jack
     
  7. constructeur

    constructeur Active Member

    Joined:
    Apr 18, 2008
    Messages:
    1,568
    Media:
    17
    Likes Received:
    450
    Location:
    Seattle, Wa
  8. Jack Devlin

    Jack Devlin Active Member

    Joined:
    Oct 16, 2011
    Messages:
    1,267
    Likes Received:
    1,079
    Location:
    Western Washington, Puget Sound area
    That's the ticket. I have a feeling that maybe some materials aren't as receptive to the chemical as others are? Don't know what the commercial process is as used by the feather merchants. UV is good. Friends use it on their Kokanee gear (fishing deep) and it helps. Good for steelhead flies. I look for UV materials. Need all the help I can get.
    Jack
     
  9. Jack Devlin

    Jack Devlin Active Member

    Joined:
    Oct 16, 2011
    Messages:
    1,267
    Likes Received:
    1,079
    Location:
    Western Washington, Puget Sound area
    Jay, thanks for the link to Caddisflyshop uv discussion. I got an education.
    Jack
     
  10. Evan Salmon

    Evan Salmon Member

    Joined:
    Jun 10, 2008
    Messages:
    218
    Likes Received:
    17
    Location:
    Onalaska, WA
    Rather than spend the extra money on what may or may not actually be UV materials, I purchased a full set of florescent markers from a craft store for just a few bucks. They work just like any markers, I can use them on materials when I'm tying or mark up flies I've purchased.
     
  11. Pattick

    Pattick Member

    Joined:
    Sep 29, 2010
    Messages:
    33
    Media:
    5
    Likes Received:
    0
    Location:
    Bremerton, WA
    I don't think that shining a UV light on materials in the store is a great way to disprove the UV label. If you shine the light on a material (like the slinky fibers) and don't notice a real difference it's probably just because the material still isn't reflecting enough UV light for the human eye to pick up. That being said, some materials definitely reflect more than others (like those hackles). It makes me wonder about what the fish sees.

    Maybe certain materials reflect so much UV that it spooks the fish? I mean, ghosts are 10 times scarier when they glow in the dark right?
     
  12. jwg

    jwg Active Member

    Joined:
    Aug 22, 2009
    Messages:
    609
    Likes Received:
    135
    Location:
    West Richland, WA
    I gotta agree that shining a UV light on the materials will not tell you if they are reflecting UV light right back, since we can't see UV light ourselves. The UV label is claiming it will reflect UV light (not whether it will fluoresce).

    The UV light test will tell you if the material is fluorescent, which is to say, it aborbs the UV light, and then re-emits visible light that we can see.

    Two separate optical phenomena.

    Its possible for a material to have both. imagine a material dyed with a fluorescent dye, and then treated with a UV reflecting pigment (like titanium dioxide) as well.

    Here is another link I just found:
    http://www.halibut.net/What-Fish-See.htm

    Jay
     
  13. Pattick

    Pattick Member

    Joined:
    Sep 29, 2010
    Messages:
    33
    Media:
    5
    Likes Received:
    0
    Location:
    Bremerton, WA
    Lol, must have been late when I wrote that... I'd say that jwg has it nailed down.
     
  14. Jack Devlin

    Jack Devlin Active Member

    Joined:
    Oct 16, 2011
    Messages:
    1,267
    Likes Received:
    1,079
    Location:
    Western Washington, Puget Sound area
    Thanks Norm, Jay, Constructeur, Evan, and Pattick. This has been an interesting s learning experience. So, all my little flashlight is going to tell me is whether or not the material is florescant. I'll just have to take the manufacturer's word as to it being UV.
    Replenished bucktail stock today at local shop and wow, lots of florescence in a yellow and a pink tail I bought. A reminder of the 60's and 70's psychedelic posters under black light and a little doobie.:cool:
     
  15. constructeur

    constructeur Active Member

    Joined:
    Apr 18, 2008
    Messages:
    1,568
    Media:
    17
    Likes Received:
    450
    Location:
    Seattle, Wa
    I think that's a reasonable assumption. Just like when dying something, I'd recon a natural feather or hair is going to be more receptive to accepting a liquid than a fine synthetic 'hair' like you show in your first post.

    That Oregon blog is awesome. Another good un' from a fella often featured on the Oregon FF Blog is : http://fishingwithjay.wordpress.com/
     
  16. silvercreek

    silvercreek Active Member

    Joined:
    May 19, 2012
    Messages:
    426
    Likes Received:
    257
    Hi fellow listers. If you will allow me a comment, I would be grateful.

    Regarding taking UV flashlights to test materials in a fly shop, JWK is pretty much right on. There is UV fluorescence and reflectance. Jack is testing for fluorescence.

    My comment is that the UV flashlights that are used for UV acrylics such as Clear Cure Goo, are really near UV lights in the upper UV A spectrum. The are about 400 nanometers and 400 nanometers can be seen by the human eye. Indeed, we can see the light from these flashlights because they are just above the 390 nm limit of the human visible spectrum. As a practical matter, if we didn't see them we couldn't tell if the flashlights were on or off.

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

    Birds, insects and fish can see further into this near UV spectrum.

    Near Ultraviolet​
    NUV​
    400 – 300 nm​
    3.10 – 4.13 eV​
    visible to birds, insects and fishes​


    http://en.wikipedia.org/wiki/Ultraviolet#Subtypes

    What the UV flashlights cannot test for is fluorescent material that responds to a wavelength that is shorter and a higher energy than the near UV flashlight emits. So although the flashlight can confirm that a material fluoresces, it cannot confirm the opposite. A material that does not fluoresce with the light may fluoresce at a shorter wavelength. For example, it may absorb UV at 360 nm and emit in the 370 nm spectrum, both of which are invisible to us but may be visible to trout (see discussion below).

    Secondly, the UV flashlight cannot test for UV reflectance in the invisible UV range. It can only test for reflectance in the near UV range that it emits and that we can see.

    Regarding trout color vision. They have 4 cones to our 3. Our "blue" cone response peak is at 440 nm. Trout also have a 440 nm cone but they have an extra cone that peaks at 355 nm, well into the UV A spectrum. This is the cone that allows trout to see well into the invisible (to us) UV range. This cone regresses as the fish ages (thought to disappear at about 2 yo) but then thought by some researches to regain function during spawning.

    So smaller trout can see deep into the UV range but for most of the year, large trout cannot see anymore UV that we can. For spawning runs such as Salmon and Steelhead, UV regains its importance.
     
  17. jwg

    jwg Active Member

    Joined:
    Aug 22, 2009
    Messages:
    609
    Likes Received:
    135
    Location:
    West Richland, WA
    I thought the flashlights for curing UV resins are peak at 365 nm.

    I am sure that some UV adhesives have their peak sensitivity at 365
    (see Norland Optical Adhesives)

    And I am sure that some of the UV flashlights peak at 365 but with a broad peak that extends into the visible where we can see some light.
    Look at the UV LED spectrum on this page:
    http://store.advancedmart.com/336ulviuvled.html

    On the other hand there are also ones with 395 nm LEDs:
    http://www.phoseon.com/technology/led-uv-wavelength.htm

    Heres an LED system specially for UV adhesive curing that uses a 365 LED, spectrum shown:
    http://www.thorlabs.us/NewGroupPage9.cfm?objectgroup_id=4424

    Jay
     
  18. silvercreek

    silvercreek Active Member

    Joined:
    May 19, 2012
    Messages:
    426
    Likes Received:
    257
    Most of the multiple and single LED UV flashlights and even the laser pens peak at about the 390-400nm range. This is in the range of human vision. I have seen one vendor advertise a UV flashlight at 375nm but the vast majority of the IDENTICAL flashlights are advertised from 390 - 410nm. Most of these were advertised at 395nm so I think the 375 is a misprint.

    If the light were a true 365nm light it would need a spectrum spread into the 390+ range for us to see it. So the spread would have to be =/- 30nm or a 60nm range.
     
  19. Norm Frechette

    Norm Frechette Googlemeister

    Joined:
    Oct 16, 2004
    Messages:
    624
    Media:
    6
    Likes Received:
    96
    Location:
    Norwich, CT
    time to read and understand the new book

    [​IMG]
     
  20. jwg

    jwg Active Member

    Joined:
    Aug 22, 2009
    Messages:
    609
    Likes Received:
    135
    Location:
    West Richland, WA
    [/quote]
    If the light were a true 365nm light it would need a spectrum spread into the 390+ range for us to see it. So the spread would have to be =/- 30nm or a 60nm range.
    [/quote]

    The 365 LEDs do have a very wide spread, with intensity out into the human range of vision. Here is the emission spectrum for one of them, from one of my links in the provious post.
    Screen Shot 2012-08-15 at 7.50.45 PM.png

    I am not arguing that all UV flashlights have a 365 peak, but some do, and they have some visible light.

    I would be curious to get some links to some of the 390 UV flashlights. Most UV flashlights I see don't specify at all, which I find frustrating.

    Jay
     

Share This Page