Quote:
Originally Posted by Crushellon
Thanks for the replies, there's some interesting points to consider there.
I don't understand the short exposures though, if the 1600 can do long exposures at neutral gain settings why are they commonly used for short subs and lots of them? What's the benefit to it? Surely longer exposures are better for NB imaging, or does it not matter so much because the background has a low noise level with the 1600?
Also, if used at low gain settings, are you just holding back the capabilities of the camera unnecessarily? As in, if I did 20x600subs at low gain and 20x90sec subs at a higher gain, would the resulting amount of signal captured be the same? Therefore making the longer subs redundant? Or would you have to do 130x90sec subs to match the amount of signal as the 20x600sec subs?
I'm just trying to get a better idea of why they are "generally" used for sort subs and lots of them to make up integration time rather than fewer long subs. The main reason I'm trying to figure this out specifically is because the idea of capturing and processing 100's of subs does not sound desirable to me at all. Measuring weights, registration, local normalisation, integration, then at the end something didn't work out right and you have to go back and find the issue within 100's of subs... uggh makes me shudder, lol.
But in saying that, if lots of short subs is the best way to get results with the camera (even if it is capable of longer subs), then that's just how it is.
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I'm not best placed to technically answer this (I still have my L plates on!), but hopefully this thread on CN helps:
https://www.cloudynights.com/topic/5...sheet-no-math/