The Color Orange

[overmywaders]

gingerdun,

Upon reflection, you could make a suitable water tank quite easily. It doesn't need to be deep, just deep enough to have at least an inch of water over the fly (so you don't get distracted by Snell's window). And it only needs to be long enough to provide some measure of UV scattering from suspended particles. Some plastic eave-troughing with plastic caps at each end should work. Cut out a circle at one end for the filter to be fixed in with silicone, and "Bob's your uncle!" You would need to firmly fix a device to hold the fly - you would only need to focus once that way. Use it outside for optimum UV spectrum. Between the UV loss to the filter, each glass element of the lens, and the sensor, a trout probably has a thousand times the UV sensitivity of the camera.

Just some thoughts.

Regards,
Reed

[DUBBN]

So who's doing this experiment?

[William Anderson]

Can we get someone who knows about such things to list the top 10 most UV reactive materials. I know there are some things on the market that peddle their wares as UV sensitive materials, but in terms of natural materials. I still don't have a clear idea of which materials are going to show significant changes in the pics. I would be completely guessing if I took a shot at it.

w

[gingerdun]

Now that I have foolishly proposed this experiment, I must keep some distance, as I am up to my eyeballs in photographing trout flies for my own book, along with all the other editorial duties.

While I have a Canon 5D camera, several good lenses, tripod, Speedlight flash, etc, the water tank and waterproof case for the camera seem beyond what I can undertake now.

Lance

[overmywaders]

Lance,

I'd be interested in learning what you use for layout software. PM me, if you have a moment.
As for the other things, your Canon would require the ICF to be removed and replaced with quartz - not cheap. Your lenses probably have too many UV-stealing elements; many find that Cooke triplets are the best for UV work. That particular flash wouldn't give much UV; natural light or a good mercury HID or special UV LEDs are the order of the day.

Regards,
Reed

[Otter]

Hi Otter,

I'm not one of those who would question a mother's wisdom; that would be churlish. Further, I have never seen any evidence to disprove her insight.


Here is the bit about the bars standing out against a light background. For illustrative purposes I will use photos I have which are of an Adams dry.
First visible light -


then in the UV


then lighten the background and set to greyscale (so you don't see the bars because they are a different color)


So the barring of the Grizzly hackle and hackle tips is still high contrast against a light background. Just so the partridge.

Regards,
Reed

Indeed my mother would get upset, not just for having a thick son, but also one that is pedantic - a right mess, that combination.

I kinda understand the pictures you presented to illustrate what you believe to be the case - through your tricks of the trade - you have detected UV reflection and represented it in the visible spectrum. In a sense you are taking an Xray - which gives you the solid silouette - fair enough - but that silouette is little different than taking a picture in the visible spectrum and removing the background - as in below - hope u dont mind me borrowing your photo and greyscaling it



So at low light conditions , which silouette is the trout going to see, the silouette in the human and trout visible spectrum or the silouette in the UV spectrum - or something completely different.

Another factor that needs to be taken into consideration when evaluating what happens at dusk and dawn is that a trout has a greater range in the Red spectrum than humans - thus their detection of red in low light conditions can still exist whereas green and blue objects may appear in silouette in such conditions. So I propose that because mr trout can see red in low light conditions it can detect a fraud if the natural appears in silouette but our fly is still highly visibly red and vice versa.

Still skeptical, but hell, if I debate and think, i may learn something and then someday , ma may say, "son yer not as thick as yer brothers"

[overmywaders]

Otter,

You said:

I kinda understand the pictures you presented to illustrate what you believe to be the case - through your tricks of the trade - you have detected UV reflection and represented it in the visible spectrum. In a sense you are taking an Xray - which gives you the solid silouette - fair enough - but that silouette is little different than taking a picture in the visible spectrum and removing the background - as in below - hope u dont mind me borrowing your photo and greyscaling it

If you eyebrow goes much higher, you can do a comb-over.
I don't think "pedantic" is my first choice.

In no sense was I "taking an X-ray". All of the flies in the book lack a background in the UV photos precisely so that people would understand that the UV light coming to the lens and sensor was reflected only from the fly itself. What is depicted is not a silhouette against a backdrop, but the actual reflection.

Regards,
Reed

[overmywaders]

All,

I have been informed by one of the forum members that none of you, and he included himself, will be able to accept the existence of ultraviolet reflective properties in trout flies merely on the basis of the study I performed with the 22 most popular dry flies (of 1984). According to him, you (all of you) will only acknowledge it to be true if your prize wet flies undergo the same scrutiny.

In short, you (and I don't really know who "you" is) have been portrayed as incapable of simply extrapolating from the approx. hundred UV images of fly tying materials and tied flies, the simple fact that grizzly hackle on a dry fly will probably appear similar in UV characteristics when tied on a wet fly.

I told him he is wrong, you (again, I don't know who "you" is) are not without the minimal cerebral functioning necessary to make the leap from dry fly to wet fly. I have better expectations of you.

I wish you the best in your experiment. I will not assist you, this is your enterprise.

Good luck.

Reed

[Otter]

Otter,

You said:

I kinda understand the pictures you presented to illustrate what you believe to be the case - through your tricks of the trade - you have detected UV reflection and represented it in the visible spectrum. In a sense you are taking an Xray - which gives you the solid silouette - fair enough - but that silouette is little different than taking a picture in the visible spectrum and removing the background - as in below - hope u dont mind me borrowing your photo and greyscaling it

If you eyebrow goes much higher, you can do a comb-over.
I don't think "pedantic" is my first choice.

In no sense was I "taking an X-ray". All of the flies in the book lack a background in the UV photos precisely so that people would understand that the UV light coming to the lens and sensor was reflected only from the fly itself. What is depicted is not a silhouette against a backdrop, but the actual reflection.

Regards,
Reed

Thanks Reed for clarifying that and thank you for your patience with me, call me what you want, I don't mind.

I now have a better understanding of what you are presenting. You have to appreciate that for thickies like me it can be hard to get a handle on such specifically scientific subject matter - though mathematically top notch at school and took a maths degree at university I was second rate when it came to applied maths and also second if not third rate in many aspects of physics.

I know this is circular which is regretable and I'm not in this instance being pedantic - If adult trout do see in the UV spectrum, clearly or even with limited vision in this spectrum, then ( and this is a question , not an answer ) is it credible to simply look at UV reflectance for unless a trout can switch off the cones that operate in the visible spectrum the picture reaching his brain for analysis will be that which is generated from both UV and his RGB receptors. I doubt that it would be credible and one would need to consider both spectrums in fly design for during the times that we mostly fish they are not mutually exclusive.

This is a very interesting topic , educational and thought provoking on many levels.

[Otter]

One dillema for anglers as far as fly design is concerned, how can we take what we can see in the visible spectrum of a prey item (insect in one of its states) and incorporate what we cannot see and be sure that the resultant image will be a match for the trout.

My reasoning behind this is if it is taken that trout do indeed see the UV releflections as depicted by Reed and if my ASSUMTION that the image thus presented to the trouts brain is its interpretation of the wavelengths from UV through to red is correct, and my ASSUMPTION that trout cannot at will switch off their RGB cones then the resulant image will be a result of a combination of these wavelengths.

As REED kindly expained at the start of this thread, Yellow is a combination of Red and Green, more Red you get Orange. So lets take an Orange material with say a UV1 reflectance level (UV1 being a measurement of the particular material to reflect UV) , we get an Orange-UV1 image, used Orange with UV2 relectance level we get Orange-UV2 image, Orange-UV3 image etc...............unless a trout interprets these differently from us as colours, then we have a spectrum of OrangeUV-shades visible to a trout.

So the next issue is , does the trout require a precise image to match the natural for our flys to be optiumum. If so then UV-Reflectance level of the material and its RGB colour must be correct to present the right image to a trout - if not then is there a point to all of this - unless we fish when there is zero natural light and can match the singular UV image of the prey with a fly with similar UV image.

Reeds assessment of the potential of UV being incorporated into our flies at this moment in time hinges on two points IMHO, first that a trout sees UV, secondly that we can reproduce flies using knowledge of UV materials into our flies.

One thing that does need discussion is "the ultraviolet reflection dominates the visible light" - it may dominate , but its domination cannot be taken in isolation - or any results of looking at it in isolation taken as absolutely relevant.

So until more concrete evidence of teh relevance of UV is ascertained , I remain skeptical, but the door is not shut closed.