Do you need a gain value with each color filter and Ha filter?


I know some people capturing the gain value for each filter for mono CCD cameras, as you can see in this post: Gain settings with filters - Sequence Generator - Main Sequence Software

I have a QHY9M and after some research, some people just capture the gain value for their most luminous filter (in my case, it would be green, as I have R,G,B,Ha & OIII but some other people they do it for each filter.

My question is, what is the best practice? I don’t mind doing it one way or the other way, but what works better? I know that my green filter will let more photons of light go through the filter faster than my Ha 7nm filter, hence, it would make sense increase the gain for Ha filter, but what is most common practice?

If it’s better to do it for each filter, is there a way to have the gain value assigned to the profile manager, so it does not have set for each event?



There is no need to use any filter when setting the gain, just point the camera at an even light source

If you set different gains and/or offsets for each filter, then you would need different sets of bias and darks to match the gains for each filter for lights. This would be a huge nightmare managing calibration files.

No need to set different gains for LRGB filters. Maybe different gain for NB filters but you will need another set of bias and darks.


Thanks everyone. This is very helpful.