El Corazon wrote: 560 mm focal length is not enough for planets. You need about 10x that to get a decent resolution. Also, PA is really not that critical for shooting planets. That can be done even with an Alt/Az mount. You should be able to polar align just fine with your regular camera and lens as long as the field is not too wide. I would guess anything above 150 mm for your camera should work just fine, as long as the FOV angle does not exceed 15 degrees.