042 Galaxy
A snow covered tree lit by mercury vapor street lamps with the moon overhead diffracted by a P042 filter.
This second image has the same exposure except that I rotated the filter while the shutter was open.
If you mount the camera on a tripod and use a time exposure longer than 1/2 second, you can obtain three concentric colored rings instead of the ray patterns : Simply turn the filter during the exposure.
"Citrus Sunrise" is a double exposure
Exp#1: The grapefruit and tangerine slices were done with a P026 (warm) to correct for the flash.
Exp#2: A small flashlight was positioned a bit below the field of view in the center and a P042 Diffractor Galaxy was used to produce the rays of color without showing the point light source. Both exposures were done with a 135mm telephoto lens.
If you compare this with the others I did with the snow-covered tree, you will see how focal length changes the effect. On those images I used a 24mm wide angle lens. With a telephoto lens you only get part of the diffraction pattern.