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Old 19-09-2021, 10:55 PM
Startrek (Martin)
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Startrek is offline
 
Join Date: Dec 2017
Location: Sydney and South Coast NSW
Posts: 6,053
Quote:
Originally Posted by The_bluester View Post
Actually, one thing I did not think to ask, were you using any filter? You mentioned having three distinct peaks in the histogram, one for each colour channel (As you would expect) Were all three peaks away from the sides of the histogram with no stretch applied? If any one channel is clipped on either side of the histogram the flats won't work correctly as the data range will be skewed.

I mentioned the filter as when I was using a HA filter or an Oiii filter with my 2600MC I had to skew the requested average ADC for the flats downward to account for in the case of HA, three in four pixels having virtually zero data (Given the signal shows up almost entirely in the red pixels) and for Oiii one in four without much data.
Paul,
Yes if you look back in the thread I’m using an L Exteme OSC narrowband filter
In regard to the histogram last night I think it was clipped ( up against the LHS and RHS )
Tonight I’ve lowered the illumination which has produced a Histogram that is not touching the LHS ( only at the bottom or base of the peak but moving away as it arcs up over and a good distance from the RHS ) However exposure time to achieve this Histogram is 15.25 sec for an ADU of 30,000
I’m going to save this one and experiment more , late night ahead
Cheers
Martin
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