Spiderweb Optics and Intricacies

June 05, 2024



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Photographer: Richard Cline
Summary Author: Richard Cline

As a retired optical engineer, for my amusement I've been trying to better understand spiderwebs. The color resulting from diffraction processes is fairly well understood, however, as far as I can tell from studying the literature, explaining the micro features (patterns and structures) that can be detected at high magnification is much more challenging. 

The above webs were photographed in my yard in Santa Barbara, California a few years ago, though I'm not quite sure of the species of spider that weaved them. The lovely 3-dimensional effect in the top photo seems almost unbelievable. Note that from my observations there are four places where one can observe the color pattern on a spiderweb: two patterns on the front side, at different focal planes; two locations on the rear side. Most people are surprised to find even a single-color pattern. But the more carefully I examine these webs, the more I'm more confused. Any insights readers may be able to provide, I'd be happy to discuss.

Photo Details: Canon Rebel camera; macro lens with extender.