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Using the brain with high gain
Posted: Mon Mar 12, 2018 7:18 pm
by donboy
In using the Brain I see that there is a setting for Maximum Dynamic Range or Unity Gain, but none for lowest noise.
What should I do to evaluate a high gain setting say on a ASI294 at 400 gain.
Don
Re: Using the brain with high gain
Posted: Mon Mar 12, 2018 8:39 pm
by admin
Hi Don,
just set a maximum exposure in the brain options - that will force the suggested gain up if the read noise limit criteria cannot be reached at low gain but can with a higher gain. See this answer for a little more detail -
viewtopic.php?f=17&t=681&p=3228#p3228
Increasing gain at fixed exposure only gives a very small increase in final stack sensitivity (due to the drop in read noise) - see the 'Detection Threshold Simulation' tab in the brain window. However this is offset by a more significant drop in final stack dynamic range as you increase gain - see 'Relative Stack Dynamic Range' tab. This means that the only good reason to increase gain beyond the levels suggested by the brain is to limit sub-exposure duration.
cheers,
Robin