I plan to try out with my humble phone camera and share the screen on the laptop where I can run CC Fingers crossed for this weekend

My first attempt to colimate my telescope was with phone camera too. But I quickly realised, that is impossible to place phone at exact center of focuser tube. That wouldn't be issue if at least you could place phone everytime at exact same spot near the center, but that's is just impossible. At least it was for me. What's the point in collimating telescope if your optical path constantly changes? Sure you can do collimation each time you take phone off and back on, but good luck with that. It will be OK for visual observation, but not for astrophotography.

That's why I'm using Rraspberry Pi camera with special case designed and 3d printed. It can be screwed on top of my focuser. This way optical path stays the same while collimation scope and when I'm doing astrophotography. Even if I take my camera off and put it back on.

I hope my explanation make sense for you, why I think using phone camera is not good idea.

Good point. So I think the most practical & relatively low cost solution is use cameras such as the ZWO ASI224 or ASI120 along with the wide-angle lens thats bundled with them

Yes I think that's the best option. If your ZWO act as standard usb camera, you can activate it's video stream directly from CC application, see version 3.2.0-beta3 here github.com/sajmons/CollimationCircles/releases.
If your camera supports absolute focus, you can control that too from CC (see camera controls button for that). With that you get hassle free colimmation of secondary and primary mirror. All you have to do is to change your camera focus distance from within CC app.

I'm not quite sure if this is working in latest version, but I'm working on it and will be available in final 3.2.0 version.

I will try it out this evening. If your application can support ASCOM, INDI then that should be able to support most of the popular cameras.

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.