Close-ups of butterfly wing scales! You should definitely click on these images to get the full detail.
I’ve paired each amazing close-up (by macro photographer Linden Gledhill) with an image of the corresponding butterfly or moth. The featured lepidoptera* are (in order of appearance):
*Lepidoptera (the scientific order that includes moths and butterflies) means “scaly wing.” The scales get their color not from pigment - but from microscopic structures that manipulate light.
The great science youtube channel “Smarter Every Day” has two videos on this very subject that I highly recommend:
At my job I am sometimes called to do demos of an atomic force microscope (AFM), which can give you exquisitely detailed topographic images.
The sample I like to do for demos for the general public is the scales of butterfly wings. (All images below are my own)
This is a light microscope image of the wing I usually look at when I run demos. You can see it looks about halfway between the second and third image, with shiny bright green scales interspersed with black scales. (The lighter area has been damaged; I got these wings from an entymologist that literally pulled two from a sandwich baggie containing dozens of wings so they were not in perfect shape.)
A little less beautifully-lit but it’s the same general idea. Each one of these scales is (very roughly) about 100 x 200 microns, within the same general size range as the diameter of a human hair. If you’re really observant you may notice that there seem to be little bright dots in the shiny ones. (This is also pretty apparent in the first image on the original post.) Cue the AFM.
This is a 20x20 micron image, so about 1/10 the surface area of a single scale. It’s a false colored topographic image so you can see what’s going on.
The first time I went to take these pictures I was doing so with some undergrads who wanted to see what an AFM was, and as we were getting this image, I blurted out “Holy shit, it’s a bike reflector.” And so it is. Bunch of curved mirrors so that the surface looks shiny no matter what angle you hold it at.
Zoom in a smidge more? Why sure.
This is a 5x5 micron image, just looking at the edge of one of those “reflectors” on the butterfly scale. See that finer texture there overlaying the surface of the “reflector”? If my math is right the spacing is just about right to absorb red wavelengths. The green is what gets reflected. Do you get this? The butterflies don’t have different pigments in their scales, it’s the *physics of the scale structure that makes it look that way*.
Okay, let’s look at one of the black scales at the same 5x5 micron magnification:
Same. Magnification. Different. Structure. You’ll notice that the photographs in the post above generally avoid the darker areas, it’s because they suck up so much light that they’re friggin’ hard to get a good picture of, as you can see in the light image I included. Those tortuous structures just absorb everything.