PlateSolve2 not working with DSLR

I am temporarily back to imaging with my Canon 550D DSLR due to problems with my CCD. When using the CCD, PlateSolve2 worked quickly and solved every time. When I switched to the DSLR on the same target it almost never solves even though I can see the target in the preview, so it’s really close. I have tried setting the FOV parameters in the PlateSolve2 window but it just keeps searching. One time, it solved the first time, adjusted the scope by a very small amount to correct 20 or 40 pixels and then the PS2 failed. Interestingly, failed too.

Tonight I was on the same target, PlateSolve2 failed, as did a local installation of but when I switched the plate solver to Elbrus (which I have a terrible time getting to work), it solved immediately and centered the target just fine.

I’m imaging at 420mm FL so my FOV is about 3x2 deg.


Hello Chris

When using my Canon 7D, I have to change the min/max star size under the Edit Parameters to get PlateSolve to preform a match all the time. If I remember right, I raised the min star size in pixels. PlateSolve2 seemed to extract some artifacts as stars. In other words, It seemed that more stars are not always better if some of the stars extracted are in fact not stars. When PS2 is trying to match a plate, look at the image and look at what PS2 has extracted as stars.

Steve B


I’ll give it a shot.


Well, I played around with the settings a bit and could not get PS2 to solve my DSLR image. Went back to Elbrus and online Astrometry which worked.


Hi Chris,

Did you remember to change the pixel scale for the plate solver in control panel when you changed cameras? Don’t ask how I know about this…:slight_smile:


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Yes, I have the pixel scale correct. I have my equipment stored in profiles based on camera, scope.

I had PS2 working great on a target last week. I changed target last night and even though I could see it was right in the middle, PS2 failed, as did my local I switched to Elbrus and it solved immediately as did the online astrometry with the same exposure.

Maybe a feature request: Add a second backup plate solving option before going to a blind solve?

I seem to be able to get one or the other working on a target but not all targets with the same exposure. Sometimes PS2 works, sometimes it is Elbrus, sometimes astrometry, sometimes they all fail even though I can easily see my target in the preview window dead center.


I have a DSLR and have played with PS2 a fair bit. I’ve tried both of their libraries and different settings trying to get as close to 100% as possible. Regardless of what I do it gives me fast solves about 80% of the time and fails the other 20%. I did change the number of areas searched from 999 to 100. It rarely goes past 30 to solve so waiting for it to go to 999 before fallback to blind solver is too long. Considering I previously only used a local I find this combination a real improvement.