Diffractors
These filters have millions of engraved prismatic grooves that like a prism, diffract the light into its spectral colors, but without distorting the image.
Helpful hints :
Whenever possible, this filter should be used with another Filter to color or darken part of the picture. This will enhance the diffraction effect.
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.
