ZWO Cooled camera noise?

[Saturn488]

I am using an ASI178MM-Cooled and I find my images come out noisy. My gain and offset isn’t set very high and the camera is usually at -20C.

My exposures are 180 seconds.

Does anyone have any issue with noise using cooled cameras?

[that_guy]

can you post a sample image? Hard to diagnose the problem without seeing the issue.

[Saturn488]

Actually I have just noticed when stacking my LRGB channels seperatly in DSS they all come out as RGB, then I need to convert them to Grayscale in PixInsight.

This might be why I am getting the extra noise/grain.

[dan_iana]

1. Not really with a 1600mm-pro. Noise wise they are pretty good (unless yours is faulty).
2. Try astroflats plugin for Photoshop - we don't use any calibration frames as astroflats does the job pretty well.
3. In deep sky stacker, make sure you don't have hot or cold pixel reduction selected as this can increase perceivable noise as it can hollow out your stars making them less sharp and appear overall "more noisy".

[Saturn488]

The astroflat Photoshop plugin is pretty good, I used to use it. I just moved over to PixInsight which I am getting really good results with.

I will give the hot pixel reduction a go. I am thinking if converting from RGB to Grayscale will produce noise in PixInsight because I need to do it to do an LRGB combination.

[dan_iana]

Make sure hot and cold pixel reduction is turned OFF, not ON :). When it's ON it was making all the small and full background stars in my image appear as noise.

[Saturn488]

Just to confirm is it the hot pixel detection and removal option under the Dark tab in the stacking options?

or

Before I register?

[Saturn488]

No matter I found it!



I applied the change to a previously done image I took and there is a massive difference. My stars were coming out really blurry and pixelated.

Thanks for that!