false color to enhance faint eye stripes

[BugEZ]

For the past year or so I have been focusing much of my bug photo hobby on the eye stripes of Dolichopodidae - Longlegged Flies. Some dolis have the alternating rows of omatidia color (stripes) such as this fly


nice portrait by bugez1, on Flickr

Some have somewhat random eye colors such as this fly


ps 1 by bugez1, on Flickr

and some appear to have quite uniform coloration of the omatidia such as this fly.


ps 1 by bugez1, on Flickr

However, when processing the stack from the last photo above with "uniform" omatidia, I noticed faint stripes. I messed around in Photoshop with the color saturation and hue to produce this image

ps 0 sat by bugez1, on Flickr

and an "enhanced" photo of a slightly different pose of the same fly.


psec by bugez1, on Flickr

As you can see, stripes are quite obvious.

As many/most of the members of this forum have excellent skill post processing images, I invite you to have a crack of the third image to enhance/pull out the stripes. You have my blessing to edit away & post your results on this thread. Some description of how you worked your magic would be greatly appreciated as I am still a Photoshop novice.

Many thanks!

Keith

[Olympusman]

The eyes have it. Nice work.

[TheLostVertex]

I certainly can see it. Perhaps some sort optical filtering might bring it out further, like cross polarizing it? There is not too much that I think we can do with the jpg file, as there is not too much information to mess with in it. If you shoot in raw to start with, maybe some alternate preprocessing before stacking might also help bring out the strips.


The best I could manage for viewing with out doing a manual type of edit was to blend a black and white filter over the image. Not great effort, but the stripping is pretty clear near the top of the eye.

[BugEZ]

TheLostVertex,

Many thanks for your efforts. I can retrieve the RAW files and create a 16 bit TIFF if that would help. The black and white overlay certainly did help at the top.

My own thoughts are similar to your suggestion to use some filtering etc when collecting the images. I am of a mind to try photographing in UV (I have a UV LED ring light manufactured a while ago) and see what appears. I could also try using blue or RED LED's to take images.

Prior to the first frost of the season ( a few days ago) , I returned to the stream where I collected this bug and collected some of his kin. They are in my freezer for various experiments this winter. Once you thaw one out, you have about 3 hours to try various configurations before the eyes dry and loose their luster.

Once again, many thanks!

Keith

[TheLostVertex]

UV is certainly a good idea. I really dont know though, the only doli's I have ever worked with have had clear stripping in their eyes, so this is both new and interesting to me.

Once you thaw one out, you have about 3 hours to try various configurations before the eyes dry and loose their luster.

I wonder if you have tried rehydration as per http://www.nadsdiptera.org/News/FlyTimes/issue48.pdf and if it helped restore true or near true color? Be another interesting experiment with the more homogenous colored eyes to see if it might bring out an additional luster of some sort.

[Bill Eldridge]

The same issue of Fly Times has an article, apparently by a forum member, about a DIY LED ring light/dome light for stacking (with a lens with a decent working distance). Includes jazzily-lit example images.

[johan]

Best I could do in the time I had, a crop to speed up processing, with everything except the eyes blacked out

1) Added a low level posterisation adjustment mask to separate out reds & yellows
2) Tweaked the saturation of red orange and yellow in topaz adjust in adjustment mask. Topaz adjust gives you a slider for orange that CS4 doesn't.
3) Brought out more local contrast by adding fine medium and coarse highlight detail in topaz detail in 50% opacity vector mask over adjustment mask

Has a bit more stripe than the original I think especially at the top but as TheLostVertex rightfully says there isn't much tonal variation information in there to play with in the first place. Also begs the question is it real information or falsely shopped.

[BugEZ]

TheLostVertex wrote

I wonder if you have tried rehydration

I have not tried rehydration, thought I am familiar with the technique. It is a good idea. I will look in my boneyard and retrieve this specimen and give it at try.

Johan made a valient effort to highlight the stripes and wrote

Also begs the question is it real information or falsely shopped.

The image I posted above and requested members to play with has passed through photo shop. I did a "levels" adjust and adjusted sharpness a little. That's it, no color tweaks. I think the stripes are very faint. What has surprised me is that there are stripes at all.

Bill Eldridge has suggested I review an article in FlyTimes on an LED ring/dome light. I will review it.

I have made a 16bit TIFF of the origional that I will post on flickr when I return from a brief trip. That may have more depth.

Many thanks to all for your contributions! This is one of the things I love about this forum.

Keith Short

[johan]

Keith - I was maybe unclear -- what I meant was if the image I posted was real, my posterisation seems like fiddling beyond what's real