OK, so i know this has been discussed a million times but still find myself confused. I think i am grasping more as i read so hear goes my question.
I have been imaging for about 1.5 yrs with the ASI1600MM pro mono camera and NB filters and like my results for the most part. I have recently been told that my exposures might be way underexposed and after doing some further reading that may be the case. I have always tried to keep my mean ADU displayed in SGP around 800 or so ( still not sure if that is a good number or not) since the SGP displays the 16 bit values. So converted to 12 bit that would be 50 ADU in 12 bit. I have read in several exposure conversations that we should keep around 550 or so using 76 gain settings. I do not know what the offset is as i have been using the ascom driver for the camera. I want to start using the native ZWO driver so i can control the gain/offset values and try different settings.
When looking at my subs they appear to be somewhat overwhelmed by light pollution even at around 800 indicated ADU in SGP. My fear has always been not to go longer exposures to keep the light pollution down.
My typical subs are below:
Field flattener ( no focal reducer)
IDAS LP 2 filter at the beginning of the image train before the field flattener
ZWO NB filters
180 sec exposures
gain settings 76 ( not sure of the offset as this is not controllable using the ascom driver)
Skies Bortle 5
I am attaching SGP screenshot of image statistics and histogram. ( where should the histogram be? should it be further from the left that what i show ?)
Also attaching the same single sub and stack of HA/SII/OIII for review.
Guidance is appreciated.
Edited by flyingg103, 08 December 2019 - 09:09 PM.