ASI 183MM Cooled

timw

ASICAP_2018-09-23sharp (1).jpgASICAP_2018-09-23sharp (1).jpgHi,

I own the ASI 183MM Cooled.

I recently received my new camera and have done some full resolution videos of the moon at 19fps. The first videos were stacked in Autostakkert and then sharpened in Registax. After this processing there is a column of striped lines in one area of each image. I see this same pattern flicker in the preview screen on ASICAP sometimes but usually only when I am changing the exposure setting.

Is this a problem with the camera or maybe a stacking/sharpening problem?

I attached 2 small cropped sections of a full resolution image where there is the problem so you can see for yourself.

ASICAP_2018-09-23sharp (1).jpg

ASICAP_2018-09-23sharp (2).jpg

Please let me know if you have a thread on a forum addressing this issue also.

Thank you.

Tim

Support@ZWO

Hi Tim

I saw your email. Here I think might others will see this, so I copy my reply:

Hi Tim

Thanks for your email. I did a lot of lunar imaging myself, and I love it too. In my experience, the bandings is cause by low SNR data.

Low SNR data, usually like this, very dim, poor seeing, out of focus, optics axis is not good or something like that. It will cause the detail can't be aligned perfectly by autostakkert,

so the noise will be aligned and to be a pattern.

My solution is, focus well, use suitable exposure to get bright preview(but not overexposured), shooting under good seeings(maybe need to wait for hours looking for good seeing window).

I'm sure you will get better images in the further.

timw

Hi Sean,

Thanks for the reply.

My concern is that the banding is all in one column and no where else in the image. Also there are even darker areas in the full image (some of the maria) and there is no banding there. Surely if it is a poor SNR problem all the darkest areas should be affected?

Is there a way of calibrating videos with dark frames to help this problem?

Thanks,

Tim

Here are the bands from 2 separate images showing the same thing. This seems to occur in a specific area each time. Also, the gain was set to very low.

ASICAP_2018-09-23sharp (3).jpg

ASICAP_2018-09-23sharp (4).jpg

Sam@ZWO

can you see it in raw image?

usually, this is caused by stacking

such noise usually exist with a very low gain setting

you can set pre-blur filter in AS!2 to get rid of such noise

timw

Hi Sam,

In Autostakkert if I turn on vertical column noise calibration then there are a few frames in the video where the lines pop out really obviously, this is before stacking. So yes I think this column of lines is contained within the raw frames.

Sam@ZWO

you can try to enable pre blur to avoid stacking on such noise

timw

I never did resolve the problem except by manually removing the bad frames by exporting videos as many .tif files and then being able to delete the ones with the line artifact. I could then recombine them into a video in PIPP ready for autostakkert to use.

However it turns out it was a problem with mac OS compatibility I think. - since I installed windows on a bootcamp drive and ran the camera from that there has been no more random lines. Just thought this might be helpful for your team to know. Its not an SNR problem, its something with how the camera interacts with mac OS.

Thanks for all your help.