SGP Collimation Aid and Skywave Collimator

Hi people,

Since some time I have been using the Skywave Collimator program to collimate my RC telescope. To streamline the workflow of that collimation process, I have written a small tool for use with SGP. In particular it can do in a simple click what Peter Cox has proposed in his Youtube tutorial (with NINA), my tool will even stack all the defocused images directly so that it can be readily imported into Skywave Collimator.

While the tool is really written with Skywave Collimator in mind, so maybe a niche application, it should also help people with their collimation of a reflector in general I think, when people want to go to INTRA and EXTRA focus easily, and send the scope to the corners and back for assessing the scope alignment over the sensor.

The tool can be downloaded here: SGP Collimation Aid download |

Cheers, Mikael

Some screenshots to get the idea:


This looks very interesting and I would love to try it out.

Unfortunately when I go to download I get a “Virus Detected” message for the download, and the browser doesn’t save the file. I have tried downloading with both Chrome and Edge.

Oh, that is not good. I have temporarily removed the zip file from SourceForge, the time for me to run some detailed virus scans on my computers. I submitted the files to, which uses 14 different virus/malware scanners, of which some very famous ones like Kaspersky, Bitdefender and avast, and only 1 out of 14 scanners defected something. But there looks to be something there.

For those who did download the files, please run Microsoft Defender on your computer, it looks like it is among the virus scanners detecting this.

Sorry for the inconvenience!


That looks great!

As an aside, what is your opinion on the Skywave tools?
I am on the edge, but it’s a significant investment and I wonder if it’s worth ot for a Newtonian (vs hardware solutions).
If you use the limited model, do you end up spending a lot for day to day collimation?

For no reason Microsoft Defender started falsely identifying my program as malware, this is apparently not uncommon (a complete 3 hour anti virus scan on my PC came back without issues). I just re-compiled the project, and that appears to be enough to stop Defender identifying it as false positive.

Now it successfully passes all 63 virus scanners at VirusTotal:

The new zip is uploaded on SourceForge, please try to download Geoffrey.

I have an RC8 and this is the only tool that will collimate mine both on axis (coma free) and off-axis (balanced astigmatism) consistently. My RC has its mechanical centre off from the optical centre, so my doughnut is not symmetric when collimation is good, which was extremely frustrating when using mechanical tools for collimation.

But, I find Skywave Collimator quite slow, at least on my NUC. So one needs to be patient. I have a permanent setup, so I only need to collimate every 6 months or so (difference between summer and winter, basically). So I am fine spending 1 hour collimating. If you need to use it often, I would make sure that the PC connected to the Skywave licence is a powerful one.

I have no experience with Newtonians, so cant help there!


Thanks a lot for the advice!

Hello Mikael,

This is an awesome tool, but I’m having an issue. It looks like the camera starts exposing before the motion ends, and I end up with streaks innstead of stars. Also have timeouts sometimes. Any idea on what may be the cause? Thanks.


Hello Rui,

For the streaking stars I had the same in the beginning, but it disappeared when I included a settling time between the moment the mount stops moving (as reported by the ASCOM driver) and the start of the exposure. Probably your setup needs a longer settling time. I’ll include it as an input parameter. I’ll upload a new version shortly.

As for the other timeout issue, do you mean that there is some timeout with the frame exposure ? Do you get an error message ? Can you take a screenshot of the error message and send me ?


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Hi Mikael,

This all seems to be related to the lack of processing power from the computer/camera combo I’m using. The camera is IMX455 (60mp) based and the PC is an i3 dual core, which may be struggling keeping up with some of this stuff. Something I noticed is that the status indicators vary quite a bit between N.A, IDLE, and whatever is the real status. Also CPU usage in this process goes up quite a bit during image integration. It is also strange that SGP stays with CPU utilization of about 20% after the utility is closed.

Could it be that your utility is calling SGP too frequently for this PC to handle?


Hi Mikael,
I have tried to use your utility but when it starts it shows N.A. for the camera and nothing for the scope and focuser.
I am properly connected in SGPro to camera, mount and focuser.
I launch SGPro first, connect my hardware, then launch your software. I tried both 32 and 64 bit version of SG Pro with the same result. Anything I’m overlooking?

Rui, right now the software polls SGP every 0.5 seconds, so not a lot. I dont think that is the issue. I have a Celeron N2930 processor, not very powerful either, and it works fine. But fore sure, when SGP downloads images from that huge 60 mp pixels, or processes them etc…, that might cause some drop-outs in communication. Did you monitor how much of the CPU SGP uses when downloading and processing images ? You could try to use the “Ultra fast” analysis and NO eccentricity measure, see if that reduces the load on the CPU.

As for the integration, for sure my tool is not very advanced in the way it does the integration, so it is bound to be slow for your 60 mp images. I have a 6 mp camera, and it integrates 10 images in maybe 10 seconds, with the N2930. I dont think there is much I can do about that. I have already reduced the integration time significantly, but now I am at the limit of my programming abilities…

As for the streaking stars, that is still probably a mount settling issue, I’ll soon upload a new version.

@flamidey Sounds like there is an access issue with the API server, maybe a firewall issue ?

If you type “http://localhost:59590/devicestatus/camera” into your browser, do you get an answer from SGP ? Should look like this (can be CONNECTED or DISCONNECTED):

In any case it is worth disabling for a short duration your firewall entirely, and then launch both SGP and my tool, to see if this works. The order you start things should not matter.

I get a connection refused, even though the firewall is disabled…

I also authorized SGPro in the firewall.

I solved it. Needed to start SGPro in admin mode.

Right. I had a similar issue last year with ONE of my windows 11 machines, see this post:

When in normal mode, do you also get that popup error regarding the netsh.exe application ?

Note that you might have other issues with running SGP in admin mode, difficulties connecting to some gear etc, so be aware of that.

On my windows 11 laptop on which I developed the Collimation Aid I have had none of these issues…

I don’t get anything netsh related: I have tried to start in Admin, connect, then disconnect, quit and restart in normal mode but it doesn’t work outside of admin mode…

If you follow the other thread, I think you should try to run this in the command prompt (in ADMIN mode):

netsh http add urlacl url=http://+:59590/ user=USERNAME

where you change USERNAME to whatever username you have for the account where you run SGP. You only need run this once to reserve the url, windows will remember it after a restart.

Maybe you have another issue, but it is worth testing.

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Confirmed solved after moving back to EN language Windows 11.