Rotating an image without resizing - any ideas?

[Delboy_Hog]

Hi all,

A little while back, I took a sequence of photos of the sun, with the intention of doing a time-lapse.  Unfortunately, before my planned sequence of photos had finished, I had to move my mount and scope because the sun was about to go behind a tree (poor planning on my part, I know!).  The problem is that in moving it, I loosened the clutches on the HEQ5 mount, so the camera was (unbeknown to me at the time) rotated a few degrees out from where it had been previously.  When I've come to making the time-lapse, there's a 'jump-point' where the features on the sun's surface in the animation jump to a slightly different place.

To add to my problems, the features in Windows Photos and the various online tools that can rotate an image by just a few degrees, resize the image in doing so....so I can correct the angles so that the features appear in the same place throughout, but now the jump-point in the time-lapse is a significant re-sizing of the sun, which looks equally weird...

Has anyone made this mistake before, and does anyone know if / how it's possible to rotate a photo by just a few (probably 15 or so) degrees without re-sizing the object in the photo in doing so?

Many thanks for any light you can shed on this for me! ☀️ 

Derek

[Freddie]

The free Astro software GIMP will allow you to do what you need.

[Delboy_Hog]

Oh that's interesting - many thanks Freddie, I'll take a look!