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Old 13-02-2021, 07:08 PM
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gregbradley
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Join Date: Feb 2006
Location: Sydney
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Quote:
Originally Posted by Peter Ward View Post
I just had another long look at you h-alpha data...It's really, really, good, but does indeed show subtle banding in the extremely faint/ shadow areas
....no deal breaker....but I suspect CMOS requires a different way of doing business to mitigate this annoying artefact.
Yes I can see that too.

2 points here to handle it. One would be to use a higher gain so the banding is pushed further down by the signal.

Recommended settings for narrowband are Gain 56 and 50 offset (mode 1). I didn't use that simply because it was first light, I only have a dark library for 26/10.

The other solution if this does not work well would be too expose for longer.
I'd keep an eye on highlights blowing out and use Mode 3 for extended full well if it needed it. I used an ASI183 with 600 sec subs high gain and did not see bright areas blow out in narrowband nor banding.

I really only plan to use 3 sets of settings:

Mode 1 56/50 for narrowband and 300-600 sec subs.
Mode 2 26/10 for broadband
Mode 3 extended full well setting for really bright stars like Mr Alnitak.

If the above don't work then we are fresh out of luck.

Greg.
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