Black Swallowtail Papilio polyxenes
Black Swallowtail
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Black Swallowtail
Michael Reese Much FRMS EMS Bethlehem, Pennsylvania, USA
- MarkSturtevant
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Re: Black Swallowtail
Excellent!! On my laptop, the compound eyes come up with this moiré pattern, presumably because the size of the facets align in some way with the size of the computer screen pixels.
Mark Sturtevant
Dept. of Still Waters
Dept. of Still Waters
- rjlittlefield
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Re: Black Swallowtail
It's definitely moiré, but it's mostly (or entirely) because of the image pixels, not screen pixels. The image can be blown up to cover arbitrarily many screen pixels, and the moiré pattern remains.MarkSturtevant wrote: ↑Sun Sep 06, 2020 6:51 amOn my laptop, the compound eyes come up with this moiré pattern, presumably because the size of the facets align in some way with the size of the computer screen pixels.
These patterns are difficult to avoid completely, without reducing all the facets to mush.
But they can be significantly reduced by prefiltering the original image, before downsizing.
There are some tips for minimizing the problem using that approach, at "Reducing moiré effects in downsizing for web posting".
Switching thoughts...
Olympusman, I notice that this one is missing the finely reticulated pattern shown clearly in your recent "Eastern tiger swallowtail". Is this black swallowtail a dried specimen also?
--Rik