Weird image rotation when using Canon DSLR

I have run into a weird issue. SGP rotates the images downloaded from my Canon DSLR. It seems to be related to the way the camera is rotated i.e. right side up or upside down.
I noticed that the other night when I started imaging with the camera almost upside down that gradually changed as the scope moved across the meridian (with no flip). Roughly half my subs were rotated 180 degrees.
I have the image rotation turned off on my DSLR so I can’t quite figure out why this is happening. I have reverted back to Backyard EOS which does not do that.
The problem with images rotated 180 degrees is that they can’t be calibrated and debayered correctly unless they are rotated back. It’s as if the image is rotated but the actual file isn’t so the bottom right corner in reality is the top left corner.
I thought it might be an issue with the camera but my other software doesn’t do that.

Any suggestions?

Are you saving images as FITs or CR2?

We don’t do any rotation based on angle in SGP, it could be that the conversion from CR2 to FITs is causing this if you’re saving FITs.


I am now saving in cr2 format but that still happens.


Not really. We know this happens because the API is very fancy. There is some type of sensor that can cause the position of X=0 and Y=0 to vary based on orientation. We can look through the API for ways to turn this off, but… I might suggest seeing, first, if you can find the name of this “feature” and then checking to see if you can turn it off in the camera options (from the menu). If you do, please share so we can hunt for a programmatic way to accomplish this.


I asked this same question about a week ago:

Weird image rotation

I also have image rotation disabled in the camera but that may just pertain to image preview on the LCD screen of the camera. Some are just rotated in the SGP image window. When I look at the CR2 file in PI or PS they all have the same orientation.

Chris M

Ken I believe it’s called image rotation like Chris said. I have it disabled in the camera.
They were definitely rotated when saved in Fit/CFA format.
Last night I had the SGP set to CR2 and they were rotated in the image preview window. However, I didn’t start the session because I was afraid that the CR2 would be rotated so I switched to BYEOS. So I will have to actually start the session and then see if the actual CR2 file is rotated. Based on Chris’s feedback it should not be.

Ok. If that’s true, I will take a look at the way we are creating the preview image.

I think we will have some clear skies tonight I should be able to test it.
My preference would be to use SGP for DSLR imaging like i use it for CCD.

Ok it looks like only the image preview on the screen is rotated. The cr2 file looks fine.
It would still be great to have te preview not rotated mainly for ease of framing. When imaging with DSLR I have a very simple setup with no goto and no plate solving:)

Ok… Canon users, you may want to avoid Beta 8. There is a high likelihood that we actually made the problem worse in that build. The good news, however, is that we believe we have resolved the issue (this will be available tonight in Beta 9)

Too late. Tried Beta 8 last night and all my Canon XSi images previewed in portrait orientation. Thankfully it doesn’t affect the RAW files, but I’ll update to Beta 9 as soon as it’s available.

Alright… working through a couple other issues preventing a beta tonight. Will release tomorrow.