Quote:
Originally Posted by glend
Paul, your running that 1600 at high gain, and shooting 10 minute subs. Normal practice with the 1600 at high gain is to reduce sub times. You get less well depth at high gain and shooting for longer doesn't make it any deeper. Have a look at Shiraz's narrowband exposure chart, which he has posted here. I shoot most narrowband at Unity (Gain 139, Offset 20) and that is with 5 min subs max,i would never shoot longer subs with that camera, even at max well depth of Gain 76. When i shoot high gain (200), i drop my sub times down to 90 sec.
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Thanks Glen. I was going by Ray's target ADU above bias from those tables. On the moonless night, even at 10 mins with gain at 202, I was only getting about 500-600 ADU above bias - i.e. less than the target of 650. So not quite shot noise limited. Seems surprisingly longer given Ray's estimates of the expected times, but I guess there's things like the large central obstruction in the RC scope which will add a bit of extra time.
On the second night, I was about 1100 over bias, and so should probably have wound back to 5 mins. But I was wary of mixing subs of different lengths in the final stack. That said, the mixing didn't work out well as it was!
