Beware the Eye of Moth

Images taken in a controlled environment or with a posed subject. All subject types.

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dbur
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Beware the Eye of Moth

Post by dbur »

Canon 50D, MP-E, 53 images DMap retouched:
Image

PMax:
Image

Higher res here:
https://secure.flickr.com/photos/dbur97 ... 7823881291

rjlittlefield
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Post by rjlittlefield »

Very nice. Thanks especially for the stereo. It makes very clear that the pseudo-pupil lies behind the surface of the eye.

--Rik

dbur
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Post by dbur »

Is that a structure in the eye or just the reflection of my lens?

This moth was still alive when the photos were taken so the eye should not be decomposed as they seem to quickly do after death.

FYI:
http://greenbuildingelements.com/2011/07/08/moths-eys/

rjlittlefield
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Post by rjlittlefield »

dbur wrote:Is that a structure in the eye or just the reflection of my lens?
It's sort of both. The dark areas represent ommatidia that are oriented so as to reflect primarily the real pupil of your lens. In this moth's eye, those ommatidia comprise a dense and fairly large almost circular collection that is centered on the optical axis. When you shift the optical axis a little bit to one side or the other, either physically or using Zerene Stacker's synthetic stereo, then the collection shifts to match. As a result, the right eye view sees the pseudopupil move slightly to the right, while the left eye view sees it move slightly to the left. These correspond to a perception in which the pseudopupil sits inside the eye.

With some critters such as preying mantis, the effect can be so strong that it's really derailing when you look at them through a stereo microscope. See HERE for my best shot at illustrating that effect.

With other insects' eyes, the structure of the eye is more complicated and so is the shape of the pseudopupil. For example with some butterflies and most dragonflies, it has sort of a sparse hexagon form with a dark spot in the middle and other dark spots arranged in a hexagonal array around that.

--Rik

johan
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Post by johan »

I don't know if this is wrong (someone correct me), but I always put eyes like this down to basically having lots of tubes on the outer surface leading down to a business end. So if you look at it straight on you can see down to the bottom (dark in this case) but where the angle doesn't let you see all the way down to the bottom you're just seeing the sides of the 'tubes'. Very clear in crane flies too.
My extreme-macro.co.uk site, a learning site. Your comments and input there would be gratefully appreciated.

rjlittlefield
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Post by rjlittlefield »

johan, that explanation works well for these moths. It can be extended to work well with the butterflies and dragonflies too. In those cases the complication is that the sides of the tubes are transparent, so that at certain angles you can see the "business ends" of other ommatidia at wider angles also.

--Rik

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