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Old 16-05-2007, 05:48 PM
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[1ponders] (Paul)
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While I agree that a comparison of camera dark frames would be a good idea, won't the conversion to jpeg and then resizing and compression to 150 kb void their usefulness? If you are going to do uncooled frames some planning may be in order? Don't take this as a nay saying, I just think it needs a bit more thought and planning.

Something along the lines of, but not restricted to, select an agreed temp for the non-cooled models, specify ISO and exposure times, select exposure condition (darkened room or with something covering the camera viewfinder for example). Once the RAW exposure is taken, the manner it is converted to a Fits or Tiff file should be considered. I know that AIP4WIN and ImagesPlus deal with their RAW to FITS and TIFFS conversion differently as does Photoshop. The files could then be sent to a central person (either Raws or fits/tiffs) who can use a standard method to measure the means and standard deviations, noise etc, of the darks. Bias frames would also need to be included for subtraction from the dark frames.

The results could then be tabulated to give a better comparison. Including this with the compressed jpegs or better yet a small crop of an uncompressed image would make better sense to me.


jm2cw
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