Moon and/or low clouds causing flickering?

[Stephen2615]

Greetings,

I have read the Troubleshooting image flicker wiki entry and I was wondering if the flicker that is mentioned is caused by the software taking lots of one second exposures along with the 60 second exposure it is supposed to do at night. I noticed flickering happening during the night where there was either a bright moon around or no moon but a lot of low swiftly passing cloud. When I looked at the log, I could see endless one second images being created.

I could move the histogram into an area where the moon would not be but the swiftly passing low cloud also seems to be the problem. My camera is a ZWO 120MC-S. The mean is always very low with the dark images. If you look at the video, you will see the one second intervals are dark.

https://southernskies.space/allsky/videos/allsky-20220608.mp4

Any ideas please?

Regards

Stephen

[EricClaeys]

@Stephen2615 Looking at the video, I don't see any 1-second exposures. They go from 60 seconds to 13 seconds, although most are 50-60 seconds. Can you post your log?

The histogram box isn't used at night.

I'm really not sure what can be done about this type of flicker. If one 60-second shot has no bright clouds, the brightness might be ok, but then if the next 60-second shot has a very bright cloud, the shot will come out very bright, and the camera decrease the exposure on the next frame, which may have no bright clouds so will be dark, so the camera increases the exposure. If the clouds are coming and going, you'll see the flicker.

You can try reversing the "Version 0.8 exposure" setting in the WebUI to see if it makes any difference, and try decreasing the "Aggression" if you have the newest Allsky. It should dampen the changes in exposure.

[Stephen2615]

Thanks.

I have turned on the debug level and I will upload it tomorrow after tonight's effort. The endless 1 sec images it produces is probably a strain on the system as well. I will also look at the changes you mentioned.

[EricClaeys]

@Stephen2615 I'm curious what the log shows. I just looked at the timestamps on the video, and they definitely are not in sync with the exposure time. For example, there might be two images that say the exposure time is 60 seconds but only 2 seconds passed on the time on the image.