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Old 06-06-2016, 06:08 AM
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Slawomir (Suavi)
Amateur Photon Collector

Slawomir is offline
Join Date: Sep 2014
Location: Proserpine
Posts: 3,127
Originally Posted by Shiraz View Post
Thanks very much for the info Suavi.

if you wish to do a direct comparison, I think that you need to get all of the data into electrons and account for the different read noise (the 1600 at the gain used for the ZWO dark has >3.5 electrons read noise). Actually, thinking about it, an apples-to-apples direct comparison is likely to be quite difficult/impossible - there are just too many variables with the 1600. eg, setting the gain on the 1600 to give similar characteristics to the 690 may not be optimum for the 1600. Nonetheless, your results at least show that the two cameras are not different by orders of magnitude, so there is nothing drastically wrong with the 1600.

If your NB background is 100ADU at 0.26, you have 26 electrons sky background. That is more than the brightest dark current region in my 1600, so, for reasonable QE in the 1600, sky noise in your system would overwhelm much of the extra noise from the "glow" in a 1600 - should you ever decide to try one - but why would you with your nice camera.

edit: I am surprised that the MAD values do not change with region selection - not sure what that means.
Thank you Ray, that makes sense. As for MAD values, I read somewhere that MAD is a more robust indication of noise than AVD or in particular SD, so perhaps that's why there is no change up to one decimal point and perhaps both darks are very even in terms of their ADU values across the chip
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