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Old 06-12-2019, 07:19 PM
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The_bluester (Paul)
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Join Date: Feb 2011
Location: Kilmore, Australia
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I think that this is going around in circles.


From my point of view, understanding what input saturates the output file is the important part here. At zero gain on the ASI294 and using a fictional "Perfect" sensor where every arriving photon is converted to an electron, approx 65K photons are needed to saturate the system but it is effectively only sensitive to every fourth one and the other three won't be reflected in the output file, you might overcome that with integration of heaps and heaps of subs. At unity gain, only about 16K photons are needed. Faint stuff will be better recorded but brighter stars end up as white blobs as over 16K arrive in each colour channel, anything beyond that is discarded. "Range" wise, one gain is able to record 65K and the other, 16K photons and that is what I am most interested in. I am not concerned as much with "Mystical" discrimination that comes with actually reporting each electron as a seperate ADU step, but the fact that you can faithfully record and capture in the output file on the same image both a feature which produces just enough electrons to overcome read noise by one electron AND a feature which produces as many electrons as the pixel well can hold, and everything in between.


I am never going to tell anyone else what cam they should buy, but any future ones where the ADC count does not at least match the sensor pixel wells won't have me reaching for my wallet.


And yes, Sony knew what they were doing when they designed this sensor, for a quite different application as a security camera sensor, I am just happy we have clever engineers scouring the lists of vendors for sensors than can be re purposed as the innards of astro cameras..

Last edited by The_bluester; 06-12-2019 at 07:52 PM.
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