The SBIG STT-8300 is a Monochrome CCD Camera with user-selectable automatic image processing. These 30 second dark frames were taken at room temperature to accentuate the number of warm pixels. The first frame is unprocessed, the second frame has a medium filter and the third frame the most aggressive filter. Each shows fewer bright pixels and each has correspondingly lower noise in the image. The user can select from eight levels of filter strength to suit his needs.
When taking flat field frames of filtered images, the flat field frame must show exactly the same optical characteristics to be the most effective. If there is dust on the filter, or uneven illumination caused by the filter, this must be represented precisely as seen in the light.