Altair / APT and HCG

[rockinrome]

Hello all, trust all is well with you.
I have some confusion that I would like your take on.

I use AstroPhotography Tool (APT) with an Altair 533C camera (the IMX533 sensor).

I know the camera has a High Conversion Gain setting (HCG) with I would like to turn on and this can be done via APT - all well here.
(I am pretty sure that tle Altair (unlike the ZWOs?) needs HCG manually activating, i.e. does not make the flip at a certain gain value.)

My question is to do with Gain value. Now I know this can be a minefield depending on your camera and software and how they work with each other and what values they show.

HCG kicks in with the 533C at Gain 200 - so I have turned on HCG and set gain to 201 - is this correct do you think??

I only ask this question in light of an explanation on the NINA website. Here NINA needs you to convert the gain manually to take care of HCG. So with the IMX533 the HCG multiplier is 3.05x, so I would have to set "Gain" to (say) 70 to get it to be over 200 so that HCG in the camera is switched on......????? (I think)

I cannot set Gain below 100 in APT (this is the lowest actual gain the IMX533 can do) so I assume (again) that my settings in APT are correct and it just sorts itself out.

<and breath>

Thanks in advance
Matthew

 

[rockinrome]

I *think* I might have answered my own question.

I have just read one of my fits file headers (using Python) and two of the parameters are E[lectronic]GAIN and GAIN.
EGAIN is set to 0 and GAIN to 201 (there is no parameter for HCG), so ...... I can only assume (that word is used too much!) that HCG is on as gain is at 201 (over 200 to switch it on in the camera)

I *think*

Matthew