Odd image shape from a mosaic

I decided to get a little crazy and tried a 3x3 mosaic. Quite honestly I don’t know if this is an SGP question or a PI question, but this was set up as a 3x3 square in SGP, and When I assembled the image in PI using ImageSolver, MosaicByCoordinates, and then GradientMergeMosaic, I get this odd shape. Forgetting about everything else that needs to be fixed, why the weird shape? Again, this could be SGP, or the telescope or…any ideas?

What kind of rotator are you using to ensure the tiles are all at the required angle?

It’s a “manual” rotator (it’s a Hyperstar), however, I did NOT choose to rotate the camera, since I was just experimenting with the mosaic feature-I didn’t really care about the orientation. I’m not unhappy with the result, just perplexed.

Ok… Just asking because it looks like you rotated the mosaic canvas to your liking, but did not rotate your camera to match.

Maybe that’s what happened. When the image loaded in FMW, I just drew the tiles on the image and did not ask for rotation in the image creation. Do you think that could be it?
BTW, I was completely thrilled with the way SGP worked-it started automatically at 7pm as requested and imaged until 3 am. Meridian flip worked perfectly, focus worked perfectly, plate solve worked perfectly, etc. I was just a little perplexed at the shape of the image.

Thanks again,


It’s very likely. The odds that your camera’s angle matches the mosaic’s angle without any intervention are pretty remote.

Right. But I guess I would’ve still expected to see a 3x3 square, just rotated differently.

That’s what you have, a 3 x 3 square of images with each image rotated about 45 degrees.
AIUI there is a manual rotate option where SGP analyses a frame then pauses to ask you to rotate the camera by hand.

I’ve used the manual rotate feature many times-it’s great!