Fluorescent or Non-fluorescent

[Soft-hackle]

Mike,
Please re-read my statement. I never said objects reflect more light than received. What I said was that brighteners/additives will help reflect more light. It's a very simple statement which is easy to prove. A color on a black background is not going to appear as bright as one on a white background in the same amount of light. In contrast to ordinary colors light emitted from a fluorescent color adds to the light returned by simple reflection to give the extra glow characteristic of a daylight fluorescent material. This fluorescence phenomenon can lead to reflectance values greater than 100% in a specific part of the spectrum. Chemical additives (brighteners) can also increase the reflective ability of colors.

Mark

[Mike Connor]

Mike,
Please re-read my statement. I never said objects reflect more light than received. What I said was that brighteners/additives will help reflect more light. It's a very simple statement which is easy to prove. A color on a black background is not going to appear as bright as one on a white background in the same amount of light. In contrast to ordinary colors light emitted from a fluorescent color adds to the light returned by simple reflection to give the extra glow characteristic of a daylight fluorescent material. This fluorescence phenomenon can lead to reflectance values greater than 100% in a specific part of the spectrum. Chemical additives (brighteners) can also increase the reflective ability of colors.

Mark

The point being that those are not reflectance values, but the sum of the light reflected and the light generated by the fluorescence. Also, fluorescence generates light in frequencies independent of the light striking the fluorescent material.

Perception of colour is heavily dependent on backgrounds and on many other things.

Some info on fluorescent feathers;

http://news.nationalgeographic.com/news ... udgie.html

here for instance a figure of 14% extra "glow" is postulated for the fluorescent feathers under certain specific conditions. ( Mainly the amount of UV light striking them of course).

TL
MC

[Mike Connor]

This was the result of an extremely controversial art project;

http://www.genomenewsnetwork.org/articl ... _art.shtml

This is a genetically manipulated albino rabbit that looks "normal" in most daylight conditions;

http://www.ekac.org/gfpb1.jpeg

TL
MC

[daringduffer]

What colour would you dye that dubbing material...?
dd
[/b]

I would not dye it at all, I would use it as it is or for blending. ( Although I might dye the tail). One of the major characteristics of hair from albinos like this is the lack of pigment, so although they look "white", they are actually very translucent. This can be of major advantage in some blends. A small amount of translucent ( Clear, not white), Antron can also improve some dubbing mixtures considerably. This is obviously because of the way they transmit light.

TL
MC

I've never thought of that. How stupid of me! I have blended a lot of different dubbing but never white in the mix. I dyed some of this
but never used it undyed. I need some more, both for me and for Bill B. I ordered from "Trappern", but too late in the season. This isn't an albino and the colour properties ought to be different. Could you say in what way?

dd

[Mike Connor]

That is Lepus timidus and I don't know anything else at all about it unfortunately. I have never had any hair from this animal. I would however expect its fur to have the same properties as many other hares and be excellent for fly-dressing purposes.

Some info; http://en.wikipedia.org/wiki/Mountain_Hare

Many furs appear white because they lack pigment, these furs also often appear very translucent. Some hairs with white pigment, ( like cats whiskers for instance) are completely opaque. Translucent furs are of considerable value in fly-dressing, regardless of colour. Also, furs like these tend to take dye very well indeed, and give very bright translucent colours, assuming an appropriate dye is used. I do not usually dye single colours or white fur as I have little use for such colours. I usually dye things like natural hare fur in order to enhance the existing colours.

I have a piece of back fur from this animal;

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

But it is not as springy or "waterproof" as the ordinary hare fur, Lepus europaeus.

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

I suppose this is due to the fact that it does use burrows, unlike other hares, and therefore has not evolved quite such waterproof guard hair.

TL
MC

[Mike Connor]

This looks a lot like Lepus timidus but is only found in various American locations;

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

I would however expect the animals to have similar fur properties.

TL
MC

[skunkaroo]

Fluorescent material in flies is a subject near and dear to my heart. On the competitive circuit any possible advantage needs to be explored, and I've been pushing the limits with such materials.

There's an excellent book on light as it pertains to fishing entitled [url=http://www.amazon.ca/What-Fish-See-Coli ... 1571881409]What Fish See[url]. While I unfortunately don't own a copy, a fellow competitor Todd Oishi has delved into it in some detail and passed on what he's learned vis-a-vis fluorescent materials.

His summary--fluorescent materials maintain colour at depth. Since water essentially washes colour at depth--i.e. normally red "disappears" first and then the remaining colours in sequence (ROY G BIV), fluorescence allows for "true colour" to be reflected deeper in the water column. This means that the attractive properties of a given colour should be functioning deeper in the water column. It's also worth noting that this applies to light reflection in all directions so the same principle should apply over distance horizontally.

All that said, in practice there is definitely a point where you can go overboard with fluorescent materials. I've found through trial and error that a little bit is great (particularly in stained water) as a fish attractor, but a lot actually seems to put fish off. Also I've found that any fluorescent materials can cause catch rates to go down in slower stretches of water or where the water is highly pressured--this isn't universally the case, but personal experience seems to bear this out. A caveat to this would be on stillwaters where I've used some gawd awful fluorescent lures (ehhem boobies) and had phenomenal results--probably because they are highly visible over distance and trigger a predatory response from larger fish.

Going down the garden path a bit... I've started to think about all the various attractive qualities of flies and begun to classify them (in my own limited way) according to their effective range: i.e. near, medium and far. If fluorescent materials are a "far range" attractor, then a medium range attractor might be reflective materials such as tinsel or holographic dubbing, while a near range attractor might be movement, colour or profile. It's probably just an academic exercise, but looking at it this way it helps me think about fly design as well as application on the water--particularly with multiple fly rigs.

Aaron

[Mike Connor]

That seems to me to be a reasonable general analysis. The problem of quantifying or proving anything still remains though. This is one reason I ceased using any fluorescent materials quite a while ago. While they may work better sometimes there is no way to tell when or why with any degree of certainty. For me, this introduces even more unknown variables to an already complex situation. I have found quite a few insects that fluoresce to an extent, and there is some documentation on this;

http://www.hindawi.com/journals/psyche/2011/875250/

UV-light also attracts more insects than any other light. I used a "black" light in my garden for a while to study some insects, so they are obviously sensitive to it. Some info on that;

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

But the fluorescence of various materials which causes them to glow under various conditions is another matter entirely. It doesn't make any difference whether fish can see in the UV spectrum or not ( most studies however indicate that they can not), the fluorescence which actually occurs and is under discussion here causes light to be emitted in the visible spectrum ( in human terms), and the light emissions and wavelengths can be measured quite accurately. Fish can see these as well. ( Although of course nobody knows how they perceive them).

Unfortunately, and here in my opinion is the main problem, I do not know if a fish, (discussing trout and grayling here. I know that other fish will often take glowing objects better than non-glowing ones, but these are usually phosphorescent not fluorescent), will take something that is emitting light in preference to something that is not. None of the various trials I made with various things provided a clue to this. Sometimes they took a fly with a fluorescent tail, and sometimes they didn't, under apparently identical conditions. If the fluorescence made the flies more attractive per se then one should see a definite tendency towards them being taken more often. This is not the case.

Quite a while ago now I started a study of various common insects under UV light, but I gave up pretty quickly, because even if some fluoresce under it, ( and surprisingly many do), one can not see this in normal daylight, and if a human can not see it, there is no reason to suppose a fish can either. They may be able to perceive some colours either better or less well than humans can, and water imposes certain other limitations as well, but there is no reason to assume that making an insect brighter will make it more attractive to a trout. It might well make it more VISIBLE ( and presumably does), but this is just as likely to scare off a fish. Furthermore, let us assume fish are taking natural flies that do not fluoresce, ( or not visibly in daylight), and we are trying to imitate those flies, making one that glows is a bad imitation!

There are definitely occasions when fish will grab more or less anything that comes into their field of view, and they will also move quite a distance to take various things. Presumably they mistake some things for food, and at least mouth it before ejecting it. They may also take things as the result of aggression. But, there is no way of knowing whether fluorescence makes such things more attractive, so it would be pointless adding it.

Shiny tinsel and similar things reflect UV light, whereas many things do not. Just another apparently useless datum. But they also reflect other light, and there is little doubt that some tinsel on some flies improves them considerably in terms of catching fish under some circumstances. This does not apply to fluorescent material. There has never been any study which proved that such things will catch more fish.

Just a few thoughts on the matter.

TL
MC

[letumgo]

Intriguing conversation. I am enjoying this thread. Quite interesting range of information.

Mike - Let me add a bit of my own experience with phosphorescent materials. I have done quite a bit of float fishing in the Niagara River using phosphorescent materials (usually the clipped nose of a glow-in-the dark twister tail). I have used this in conjunction with egg sacks, when I am fishing in almost full darkness conditions. I thread the fishing line thru the glow-in-the dark nugget (roughly 1/4" long) and then tye a very small hook (size 14) onto the line and add an eggsack to the hook. Once the rig is set up, I charge the phosphorescent using a small LED flashlight. The material will continue to glow for about five minutes before needing to be recharged with another dose of light from the LED. I have tried fishing plain egg sacks, but find the addition of the glowing phosphorescent egg greatly increases the number of strikes I get. In this case, I believe the glowing phosphorescent material helps the fish see the object floating by the fish. They probably grab hold of it out of curiosity, and then hold onto it because of the taste of the genuine eggsack underneath. I realize this is not fly fishing, but wanted to add the general comments/experience regarding phosphorescent materials.

[Mike Connor]

You may also find this of some interest;

http://www.skiptonflytyers.co.uk/snippets.htm

Materials dyed in picric acid also fluoresce, and it is possible that this may make flies dressed with such materials more attractive under certain conditions.

http://www.cs.arizona.edu/patterns/weav ... t_dye6.pdf

http://www.bio-nica.info/biblioteca/Mullen2008Aves.pdf This MAY! help to explain why some feathers seem more effective on certain flies than others, but this requires considerable study.

http://www.thefreelibrary.com/Use+of+ul ... 0259154990

http://www.spectroscopytips.com/apps/bi ... -feathers/

A great deal more study is required, and the relevant correlations, if any, very carefully researched before these things are going to be any practical use to an angler / flydresser.

TL
MC