[raymo]

The chances of both lenses getting the same problem at the same time are vanishingly small, and connection camera/ lens problems wouldn't cause
ellipses, so very high likelihood the problem is in the camera. You can eliminate the lenses easily by seeing if the camera will focus when the body is
held up to a scope focuser, and the focuser adjusted. Easier still if you have a T-ring to attach the camera to the scope properly. I just had an
improbable thought: the diopter adjuster on the viewfinder hasn't got accidently moved a long way from it's normal setting by any chance. If you have
some astigmatism, this could cause ellipses.
raymo