I’m pretty new to astrophotography, but have been using Telescopius and Stellarium for a while. When I target an object based on my camera and telescope data, the FoV in Telescopius and Stellarium are consistent. However, when I point my camera/telescope to that target using an aequatorial mount, the fov is rotated by 90 degrees.
Can anyone explain?
Have you tried plate solving your pictures to see the position angle / orientation of your framing?
Maybe your camera is actually rotated 90 degrees and not with the long side towards the celestial pole?
Thanks for this hint.
I haven’t plate solved (how?) but when the mount is at zero position (pointing to the pole) the camera’s long side is in east-west direction (landscape format). So, if I understand correctly this would be 90° rotated?
You can plate solve any picture by uploading it to Telescopius to your profile - menu Astrophotography > Upload your astrophotography
After you upload your picture it usually takes a few minutes to plate solve using Astrometry.net serivce.
If the long side is indeed in the East-West direction (I assume you know this by visual inspection?), that should be a rotation / position angle of 0 degrees (or maybe 180, but not 90).