Real FoV rotated by 90 degrees

Hi there,
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?


Hi Bernd,

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 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).