You would need something better (more sensitive) than a 120mc for guiding at longer focal lengths. They are ok at f5 but it can get hard to find guide stars at times. I swapped to the 120mm for the extra sensitivity. I should probably add that I now use an OAG, the 120mc was always good enough with a guide scope.
Last edited by doppler; 14-09-2019 at 07:35 PM.
|