UV Materials - Marketing Myths & Misunderstandings

Dubbing with 'UV' in its name.

I stumbled across an article called "To UV or Not UV" on Midcurrent and it reminded me of how much this has been annoying me lately. It concerns me how little people understand about it and how much both manufacturers and retailers must love that.

Main Points

• You can't see UV, so don't get excited when someone shines a UV light on something and it glows or changes colour.
• Fluorescence isn't the same as UV reflectance or absorption.
• Natural materials can be some of the most dependable in UV.

When I talk to people in the fishing community about this, it is clear that it is far from understood. In fact, I would liken it to Otzi the Iceman's comprehension of North American geography, dub-step, or the Kardashians. Now don't get me wrong, I am not making fun of poor Otzi. With just a copper axe and bag of tinder fungus, he kicked some serious Neolithic ass.

Every article and book I have read on the subject tries to go in to the painful details of the electromagnetic spectrum, nanometers, how this relates to both the frequency and wavelengths of visible and ultra violet light, the penetration of UV in water compared to other wavelengths...This is all very good information, but by the end of it all I think most people just want to buy some sparkly stuff and go home.

Here for example, is a scene played out in tackle shops everywhere. To up the cool factor, a UV flashlight/torch is pointed at the latest UV dubbing mix and the resulting glow somehow translates in to a glimmer of hope for all the near or complete misses we tied the previous winter.

Coooool!

There's just one problem with this misdirected mid-day infomercial. Since your eyes don't see into the UV spectrum, you're just seeing a different colour of visible light being reflected back. Yes, the UV light is emitting UV along with some visible violet light obviously, but it is being reflected back at a longer visible wavelength. You have no idea what it reflects in the UV spectrum unless you had equipment or special eyeballs to enable you to do so.

The most in-depth read on fishing and UV I'm aware of is The New Scientific Angling, Trout and Ultraviolet Vision, by Reed Curry. This book is strictly for the morbidly dedicated. After reading it, I was a little disappointed that I didn't somehow pick up more silver bullets, but reality is like that - in that sense, this book does its job. It simply gives you a deeper understanding of what may be happening in different situations.

Taking the magic out of UV

Confusing Fluorescence with UV Reflectance

The priority of those selling materials to us is not to catch fish necessarily, but to catch our attention and get us to buy a product. You can't blame them, it's how they stay in business. Of course it's great if it catches fish, but the feedback on that fact is not usually immediate enough to help with sales and keeping up with the latest trends. It could be the best dubbing material and colour for a caddis pupa for example, but too boring compared to something beside it glittering away. Many, many of the materials sold as having some nebulous UV quality or the letters 'U' and 'V' in their name have a bright eye catching material in them to subliminally insinuate that we are seeing something a lot more special than it is. This isn't necessarily lipstick on a pig. It may be a great material and the shine or colour could add that extra suggestion of life in to your fly, but the UV characteristics may have nothing to do with that at all.

More Coool

WARNING! The Following Contains Painful Science

When a material is fluorescent, what is actually happening is this. A photon from the shorter wavelength light (UV that we can't see) is striking the electrons orbiting atoms in that material which excites the electron to a higher orbit. After a really short delay, the electron returns to its original energy level, releasing a photon at a lower energy level. This short delay dissipates some of the energy from the original photon so the light reflected back is at a longer wavelength (Stokes shift). It is wayyyy more complicated than this, but that is the gist of it. For more detail, click here. This makes something look brighter than materials surrounding it that aren't fluorescent. In a way, the material is using extra light energy that is already around us but is too high a frequency and short in wavelength for us to see and adding it to the visible light being reflected back that we would see ordinarily.
There are many situations where fluorescent colours make a big difference. Kokanee fanatics, salmon anglers, or folks dealing with muddy or deep water situations usually have some gear that has a serious day-glo to it. Even with clear and shallower water, there are scuds and other insects that can have some fluorescent colours on them - the tequila booby... However, this has nothing again to do with UV being seen by either you or the fish, just that it was present in the environment.

My Fly is Colour?

There's another issue or at least a point of discussion. Let's for argument's sake say that a material had UV reflectance. Knowing what you know about colours in the visible spectrum, can you imagine if someone referred to all colours as just colour and not red, orange, yellow, green, blue, violet, as we go from 700-400 nanometers? What if you were colour blind and unable to see red and after you tied a nice set of damsel fly nymphs, some weirdo took a bright red marker and added it to the nice light green marabou. It would totally change the colour of the fly and you may not have a clue. Maybe I'm way off here and trout can't really distinguish any other colours beyond 400 nm, but it seems like were really fumbling in the dark. Maybe it's just the amount of reflectance or absorption of just one more colour or 'greyness' that they perceive.

Black UV - Does it absorb UV? Who cares! I like sparkly.

Not only is it a largely invisible phenomenon to us, but we then have no idea where we are putting what frequency of UV on what part of our flies and whether that matches up with anything on the actual food item that we are trying to imitate.

Good Ol' UV Materials

If there's one thing that I've learned from my unguided investigation of UV, and with Reed's book in particular, it's that there are some very standard materials that can give you dependable results in regards to the shorter wavelengths. Nature has been using UV for quite some time. If your goal is to have high UV contrast on a fly for example, then peacock for absorption and white mallard wing feathers for reflectance can give you good results. Thanks Reed! Oh, and thanks birds!!

I'm so high up on my soap box that I can almost see over the dashboard! So yes, I think I've overdone this one. Please take a break and then read the great article on Midcurrent about the significance of UV on prey items of trout. It's probably as detailed as you would ever want it.