ZWO 183 MC Pro question

Hey Alan,

I have the monochrome version of the same camera for a while now. When it comes to settings, there's 2 things you need to be aware of:

• banding artifacts at low gain[/*]
• amp glow at medium-high gain[/*]

Most of the time I use unity gain (111) with default offset. Half unity (54) and double unity (178 )  and anything in between work fine too, but above that you lose too much dynamic range for DSO work and the amp glow becomes difficult to manage quickly, below that the banding becomes a problem (I had to throw away a night's worth of data because I accidentally set gain to 0, and it was just too horrible to fix up in post)

finally, because of the amp glow is very nonlinear, do NOT scale/optimize your darks. That includes calibrating your flats with bias and scaled versions of the masterdark. Instead capture dark flats, you don't need bias anymore then (note: this is generic advice for most cameras with strong glow, I use the same process for my ASI294MC).

references: https://www.cloudynights.com/topic/616524-sub-exposure-tables-for-the-zwo-asi183mm-and-qhy183m-and-colour-versions/

I agree with Jim and Benny. In my case I have learned that shorter exposures really make a difference as it is easy to oversaturate those small pixel wells. I do not process with bias frames and use unity gain and the default offset, I believe it is 10. Really does work well with short focal lengths. I did some work at -0- gain one time with unusable results. Terrible banding.

good luck and Clear Skies!

Hello
Thanks for the replies. I've taken various darks varying between 30 secs and 240 secs all at 111 gain and default offset.
I'm still yet to actually use the camera. Fingers crossed for some time this week….

Clear skies
Alan

Do you have any pics to show? I've yet to actually take an image 😡

Alan, as an example here's my M101 and M51:

https://www.astrobin.com/399868/
https://www.astrobin.com/398529/

I used 120s exposures back then.

Benny Colyn:
finally, because of the amp glow is very nonlinear, do NOT scale/optimize your darks. That includes calibrating your flats with bias and scaled versions of the masterdark. Instead capture dark flats, you don't need bias anymore then (note: this is generic advice for most cameras with strong glow, I use the same process for my ASI294MC).

Benny, this is the explanation i am searching for several month. I am so incredible thankful. If we ever meet in real life, i owe you a beer (or whatever your favourite drink is). Thanks a lot for pointing out that the ampglow is nonlinear. This explains a lot of strange effects. Thank you!

Michael Feigenbaum:
I am still a novice imager

  Of course, Mike...  ;)