High noise with my ASI 1600MM ?

Hi,

I've got an ASI1600 MM recently and did some galaxy imaging with it from my light-polluted backyard.

I'm using 120 sec exposures (both for luminance and chrominance) at unity gain (so 1.6e of read noise) camera cooling set to -20°C.

Background ADU is typically around 10000. At this level noise should be dominated by far by photon noise, which would be then around 100 ADU RMS.

However, the actual statistics on my subs give that the background noise RMS is around 350 ADU.

Is there an issue with my camera ?

I'm wondering if it could be the power supply (I'm using the ZWO power supply, to power the camera cooling and the ASIAIR at the same time)

thanks,

Dan

Could you share the fit files with us via Dropbox or Google Driver.

Thanks,

here is the link

https://drive.google.com/file/d/1hBKty58Jw8IVYLntS3ekoDH0UO5I7gqI/view?usp=sharing

First file is an unprocessed luminance frame

Second file is the same luminance frame with dark subtracted

regards,

Dan

We suggest you take more light image files, and then stack to reduce the noise.