Purple in Trout flies.

[Traditionalist]

I use dyed starling and other stuff for a lot of things. It is not really black, more a dark smoky grey. The "sheen" caused by overdyeing also makes a difference. The "metallic" sheen on some feathers is not pigment but the result of thin film interference. Some info on that;

http://www.webexhibits.org/causesofcolor/15.html

http://en.wikipedia.org/wiki/Thin-film_interference

Using dye one can of course only alter the colour of the pigment but this also has subtle effects on the film interference. Film interference is ( partly) the same phenomenon that causes insect wings to shimmer in colour, but makes the colours permanent;

http://arthropoda.southernfriedscience.com/?tag=fly

This, by the way is also my basic theory why fish will take some flies under bright conditions, and not in dark conditions, and also of course why they take some flies in dark conditions and not in light. The wing colours are only visible under very specific conditions, and brightest against a dark background, ( as the photos in the previous post show). This has nothing to do with UV light or anything like that, it merely requires a darker background for the colours to appear. Some feathers have similar properties. I am still researching this. The thin film interference on starling feathers being one example.

That some iridescent feathers are much more effective for various flies is known, but not exactly why, I think this is at least partially the answer.

Basically just trying to figure out why some things work well under certain circumstances and poorly or not at all under others. I know that "UV light" has been postulated as being responsible for many things but I never believed it, it's not logical and does not fit known facts. The interference colours do fit the facts. The main difficulty now is in correlating various interference colours to various fly wing colours. I am fairly confident that this will explain why starling for one is so effective under various circumstances, and also how to improve that effectiveness, but this takes time and work of course.

May also show why some mottling is so effective on flies that appear to have "clear" wings and why purple and some other colours are sometimes effective;



You can get the article as a PDF here;

http://www.pnas.org/content/108/2/668.full.pdf+html


TL
MC

[Brook]

Thanks for the replys Lads.
The colour thing's much clearer now,honest!
Alan,this hatred of fly geeks will leade to no good :lol:
Thanks Kev.

[Brook]

Alan,only joking about the fly geeks.
Rekon You're spot on with the fly tying kit,got boxes of the stuff that i'll never use,not even going to think about the cost.
Once You're hooked thats it,no going back.
If You tye Your own,You can risk them around trees,long grass and the likes.
The river at the bottom of the road is that over grown,You always loose a few,wouldn't like to be paying £1 a time for PTNs
Watch out for the next IN fly the Purple Sedgehog.

[Otter Spotter]

i love fly geeks, actually i depend of fly geeks to supply their magic, i tried making flies once, the kit cost more than i spent on fishing, calculating the cost per fly i found it way more sensible to ply fly geeks with beer

Has your patent for this technique of fly blaggery come through yet?