Astronomical Telescope Eyepieces: A Discussion for the Beginner
Recommends starting with eyepieces of magnification one-fifth of the telescope aperture, and equal to the telescope aperture. So for the SMIC 220mm telescope, that's about 40mm and 200mm. (EDIT: no that's wrong, it should be magnification, so about 40x and 220x. For my current 150mm reflector w/focal length of 750mm, that would be 150x or 5mm, and 30x or 25mm. The scope came with a 25mm eyepiece.)

Observation planning



紫金山天文台-创新团组 -