Quote:
Originally Posted by Slawomir
Interesting experiment - thank you Ray.
When you mentioned calibration - was the read noise being subtracted? Wouldn't then be also necessary to account for bits taken up by read noise in a CMOS-acquired 12-bit data, so perhaps scaling should be down to say 7-10 bits (instead of 12-bits), depending on gain setting in a CMOS camera?
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Hi Suavi
Calibration was a standard dark subtraction and flat compensation - read noise remained as is ( actually I would love to find a way to subtract the read noise
). I guess I could have rescaled the raw 12 bit data by padding out with zeros, but didn't see the point - stacking the 12 bit data showed what happened.
Sorry, but I don't understand why you suggest 7-10 bits - the 694 and the 1600 both have over 11 bits dynamic range. All I have done is chop off the bottom 4 bits from some 694 data - to show that it isn't necessary to digitise to 16 bits with an 11 bit DR CCD.