Golden Orb Weaving Spiders and Diffraction

June 22, 2011

GoldenOrb (2) 
Photographer: Phil Lachman
Summary Author: Phil Lachman

This handsome spider web has been made by a very young Golden Orb Weaving spider (Nephila plumipes). It's positioned just on the edge of its mother’s web. One of the golden strands supporting the mother's massive web can be seen running across the top of the photo. Being such a small spider, and producing such thin silk, the diffraction of the sunlight is more spectacular than that produced by the mother’s web. This little spider is less than 2 mm long. Its mother has a silvery-grey colored body that's 2 to 4 cm long with yellow-banded black legs. If the little spider is a female, she'll eventually construct a web that could be over 6 ft (2 m) in diameter! I feel very blessed to have this spider family living just outside my back door (in New South Wales, Australia) -- on the north side of the house. This means that the web captures the Sun’s light nearly the entire day, making for quite a colorful display.

Note that the depth of field of the photo is such that the top half of the web is out of focus. As you can see, this produces a different rendition of the colors compared to the focused part of the web. When the camera lens in next to the web, we intercept a wide range of viewing angles. So, we observe not a single color but a spectrum of color. Photo taken on May 7, 2011.

Photo details: Camera Maker: Canon; Camera Model: Canon EOS 50D; Focal Length: 135.0mm; Aperture: f/5.6; Exposure Time: 0.0063 s (1/160); ISO equiv: 200; Exposure Bias: -2.00 EV; Metering Mode: Matrix; Exposure: aperture priority (semi-auto); White Balance: Auto; Flash Fired: No (enforced); Orientation: Normal; Color Space: sRGB.