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Flashes of green and red during capture (ASI676MC)

Posted: Wed Feb 11, 2026 2:39 am
by Pratul
Hello: I recently started using SharpCap Pro and it works great for everything but this wierd issue? As you can see in the attached GIF, the screen and the captured SER file both show flashes of green and red. I tried:
- changing exposure (over / under).
- white balance (Red / blue ; Auto / manual)
- Different USB-C ports on the computer
- Different USB-C cables including one that I got with the camera

but they don't help. I tried doing a capture with the camera in my office and get the same behavior. To rule out issues with the cable and the camera, I did a capture with ASICap and had no issues.

Camera: ASI676MC (Bought it about three weeks ago)
Computer: Windows 10 running on an Apple Macbook Pro (i7 @3,3Ghz, 16GB RAM, 500GB SSD)
Connection: USB 3.1 certified cable connected directly to USB-C port on the computer without and adapters or hub (4 feet)

Drivers:
ASI Camera Driver: V3.27.0.0 (Latest I could find on their website)
USB 3.0 eXtensible Host Controller V1.0
USB 3.1 eXtensible Host Controller V1.10

I went thru the article on USB issues and all the requested files/details are here: https://drive.google.com/file/d/1En25Qv ... drive_link

Sample of the capture showing the issue: https://drive.google.com/file/d/1FZVHXu ... sp=sharing

Thanks for your help!

Re: Flashes of green and red during capture (ASI676MC)

Posted: Wed Feb 11, 2026 7:14 pm
by admin
Hi,

is there any chance that the settings for the white balance controls on your camera in SharpCap are set to 'Auto'? The colour changes in that animation look to me like the sort of things you would see if the white balance controls where being adjusted almost at random. I can't imagine that sort of thing happening for no reason, but if the white balance was set to auto then maybe the 'auto adjust' code in the ZWO SDK is struggling to find what it thinks is a good white balance and keeps making adjustments, leading to what you see.

You will find the white balance controls in the 'Image Controls' block of the controls on the right. SharpCap by default may be restoring the settings that you used the last time, including 'auto' for white balance if that has been set at some point in the past. Other software however will not put back the same settings when you open the camera.

cheers,

Robin

Re: Flashes of green and red during capture (ASI676MC)

Posted: Thu Feb 12, 2026 2:11 pm
by Pratul
Hello Robin: thanks for your reply. It is indeed set to auto. I thought setting it to auto would fix the issue (not cause it :) ). I will set it to manual the next time I do a capture and see if that fixes it.

Thanks for your reply and developing this awesome application! I have been using it for a few weeks now and absolutely love it! There is so much to learn and try but not enough time with clear skies ☹️

Re: Flashes of green and red during capture (ASI676MC)

Posted: Thu Feb 12, 2026 2:40 pm
by admin
Hi,

hope that the colour balance set to manual helps. It can be well worth testing out the software and the camera in daylight, either through your telescope and pointing at a distant tree/building, or by fitting a 'C' or 'CS' thread lens to the camera (these are usually fairly cheap, especially if you are prepared to wait for delivery from china - they screw into the C thread on the camera or via a T-to-C adapter that comes with a lot of cameras).

You can also use previously saved SER files to practice using SharpCap's features - just run SharpCap and drag an SER file into the picture area - SharpCap will open the SER and play it back on repeat via the 'High Speed Test Camera', letting you try out features in SharpCap without waiting for clear sky.

thanks,

Robin

Re: Flashes of green and red during capture (ASI676MC)

Posted: Thu Feb 12, 2026 11:15 pm
by Pratul
Good to know! I will try them both. Thanks!