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Old 05-06-2016, 01:44 PM
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Shiraz (Ray)
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Location: ardrossan south australia
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A far better way to analyse the darks is to use the local SD (excluding outliers). This will provide an idea of the shot noise due to the dark current and you won't pull in any fixed bias structure (which will be subtracted in calibration).

The dark on the ZWO website was taken at an inverse gain of 5, so the difference that you measured in mean values is 26*5/16 or 8 electrons. This is more than that in the CN darks and it could mean an excess noise of nearly 3 electrons RMS if it is dark current and not just bias shift - that is significant, but it would still not be measurable in almost any other camera. To get some idea of the significance of this sort of signal, how much background sky signal (electrons) do you measure with your 3nm filters?

Last edited by Shiraz; 05-06-2016 at 02:23 PM.
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