Jupiter is a low contrast planet and I find it harder to get the best focus for detail. I find that if I just focus on a moon close by the planet, then that the best it will be to view the entire globe. I find Saturn not as difficult to get the sharpest view. Maybe I should just start on Saturn and then swing over to nearby Jupiter and not touch the focus knob?
Lately I have just been using my C102 that has a 10:1 Crayford focuser with the fine focus knob. Using around 100-125x on them.
Anyone else have a good method?