Q S I 5 0 0 S E R I E S U S E R G U I D E
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Original image
Original image minus dark frame
Look at the two images above. The top image is the original image as it came out of the
te
otes, and to adjust for any pixel non-uniformity inherent in the CCD. Pixels in a
spond slightly differently to light, typically within 1% to 2% across a CCD.
All optical systems have a “signature” which gets recorded on the CCD. This unique
signature is caused by how light travels through the telescope illuminating the CCD and
how each pixel responds to that illumination.
camera. The bottom image has had the average of 5 dark frames subtracted from it. No
that the number and intensity of bright pixels have been dramatically reduced leaving a
smoother black sky background.
Flat Fields
Flat fields are used to correct for any irregularities in your optical system, such as vignetting
or dust m
CCD all re