Refractors.

#583532
Paul Leyland
Participant

A special case of “short focal length refractor” is a lens specifically designed for the camera in question. Telephoto lenses are especially flexible in what they can be used for.  I’ve taken snapshots with a 80-300mm telephoto of star fields which look quite nice.  Never had the skill or patience to do it properly though. Those who do learn the technique have produced some amazingly good work.  You may like to try this approach to cut your teeth before spending serious money on a telescope. Invest in a good mount first.