Hi Simon, I tried it out and found it quite challenging to get the balance of gain & exposure correct for the ASI224mc (using ASICap) to show the details. Its either too dim or too bright
I need to find more time to do this more leisurely.

On what OS were you testing?

Linux Mint. I couldnt get the camera working directly via CC so launched ASICap and the manually overlaid CC on top of that window. Transparency etc were good so if I could get the image brightness correct then would have helped me follow the instructions you posted

Can you send me your log file? It's located in logs subfolder if your executable.

There is new version 3.2.0 beta5 available!

Changes are:
Finally camera controls should work for UVC cameras on Windows (through DShow) and Linux (through V4L2).
Performance improvements

Full change log: github.com/sajmons/CollimationCircles/co....version-3.2.0-beta5

github.com/sajmons/CollimationCircles/releases

Thank you Simon. I was talking with a friend of mine a couple of days ago:

"I personally use metaguide to collimate my SCT. It is now the only real reason why I would stay on ascom. A collimation aid would be very welcome."

So I recommend your software to him and he said this:

"It looks promising, though metaguide works differently. It uses an in focus star at higher F ratios, usually with a red filter or an IR pass filter to negate seeing and reveal the first airy ring around the star"

So I have no idea what to say since I've always used refractors.

Thank you Jasem for spreading the word! I really appriciate that a lot!
I looked at metaguide. It's interesting. But I dont know much about SCT's.
With CollimationCircles everything is manual. No fancy algorithms in background.
But I belive you can always use bathinov mask on SCT too and perform precise final colimation using the mask and bathinov patern in CC.