8 replies to this topic

[jstrandberg]

I went out and shot 40 2 min. exposures of M45 with my Canon 77D and for some mysterious reason the first 20 or so pictures came out in portrait orientation and the others in landscape format. I can change the orientation but cannot save the rotated photos as CR2 file.

 

So, three questions. First, is Siril smart enough to rotate the pictures to the same orientation for stacking? If so, then all my worries are solved. If not, what is the best file format to convert the images to? DNG or TIFF?

 

And last, will all my photos - lights, darks, flats and biases all have to be the same file format for stacking in Siril?

[dx_ron]

That's a setting somewhere in your camera. Look for "autorotate" or something similar and turn it off.

 

Yes, you want all the calibration frames to match the lights in file format and dimensions. The 'dimensions' can trip you up if you try to mix and match, because often the .CR2 are saved with slightly different dimensions vs a .fits

Edited by dx_ron, 26 March 2023 - 12:01 PM.

[jstrandberg]

That's a setting somewhere in your camera. Look for "autorotate" or something similar and turn it off.

 

Yes, you want all the calibration frames to match the lights in file format and dimensions. The 'dimensions' can trip you up if you try to mix and match, because often the .CR2 are saved with slightly different dimensions vs a .fits

Well, auto rotate was on, so hopefully that will prevent it from happening again. Still have to figure out how to stack the images it took.

[rj144]

Siril will stack them fine.

[Oort Cloud]

I would give it a try, Siril can go well beyond simple rotation, which is common when using alt-az mounts or when PA is off with EQ mounts. Just leave the registration method on the default of homography and you should be fine I would think (although any other than shift, which cannot handle rotation, should work too). I'm curious though, why you came to ask before just trying it. If it doesn't work, it's not going to break anything, it will just give you an error message in the console explaining why it failed (unless if your using scripts, which I always forget that Siril has, because manual is so much better IMO).

And while Siril can work with many image formats, the best practice would certainly be to use the same format for all of them. I'm not sure why this is a concern though if you're using the same camera to collect all of them.

Edit: I realized as soon as I posted this that the scripts are still run with the application open, so you would probably still get an error message in the console if it doesn't work.

Edited by Oort Cloud, 26 March 2023 - 02:09 PM.

[BQ Octantis]

The rotation of a raw image is just a flag in the EXIF header. There is no actual rotation to the data, so stacking with Siril is unaffected.

 

If the orientation bothers you, you can batch remove the EXIF rotation flag from your .CR2 library with ExifTool with the following command:

 

exiftool -Orientation=1 -n *.CR2

 

Hope that helps.

 

BQ

[RPitts62]

Do you have an application from Canon for downloading your images to computer? For using my Canon T6, I have software I downloaded when I got my camera, something like "Canon EOS Utilities", or something like that. I use it to export my images from the camera to my computer. That program allows you to rotate your images if they're in the "wrong" orientation before exporting. Early on, I did the very same thing you did and forgot to turn autorotate off, but I was able to correct the orientation before I even stacked them. I don't know about your camera, but you may also have a function to rotate them in camera as well.

 

Randy 

[rj144]

Do you have an application from Canon for downloading your images to computer? For using my Canon T6, I have software I downloaded when I got my camera, something like "Canon EOS Utilities", or something like that. I use it to export my images from the camera to my computer. That program allows you to rotate your images if they're in the "wrong" orientation before exporting. Early on, I did the very same thing you did and forgot to turn autorotate off, but I was able to correct the orientation before I even stacked them. I don't know about your camera, but you may also have a function to rotate them in camera as well.

 

Randy 

As explained in the post above yours, orientation does not matter. It's only for display.

[jstrandberg]

Thanks for the tips. I will forge ahead.