Quote:
Originally Posted by Poita
I see what you mean, but the photons are not necessarily appearing every second, and the subs aren't contiguous.
So if say a photon (drop of rain) arrives every 10 seconds or so, and your bucket is being emptied every other second (your chip is being read) then you may never collect those photons at all.
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No because some of your subs will catch some and others won't.
Quote:
Originally Posted by Poita
Also, if you were only capturing one photon, instead of 10 (with a sub 10x longer) then it would be harder to distinguish from the noise floor. With a 'quiet' sensor, this could make a big difference.
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That's what calibration takes care of.
Quote:
Originally Posted by Poita
But I could be completely wrong, I'm only going on a thought experiment here, I haven't gone back to the books to get hard data.
I'll try taking 600 one second subs and a 10 minute sub and compare the two.
Also, the longer the shutter is open, the more 'averaging' happens automatically rather than averaging later if you know what I mean.
If short subs could capture everything, then I'd be always doing one second ones, no aircraft or satellite trails to worry about 
Surely someone has already given it a go.
There was a discussion here a while back on how to calculate the maximum effective sub time for your light pollution and camera, I'll try and find it. |
I'd agree that practically the longer you can go the better. Under dark skies. I have a mate who does routinely in excess of 1h subs but he has done a lot of homework on guiding and flexure. But it works.