The equipment that is sold for "this lets you do amazing things" is the worst equipment for general purpose use. In this particular comment, the magnification o

The equipment that is sold for "this lets you do amazing things" is the worst equipment for general purpose use. In this particular comment, the magnification of a telescope is the ratio of the primary (mirror or lens) focal length divided by the secondary (eyepiece). An entry level scope might include a low magnification 25mm lens and a high magnification 10mm lens, but going down to 4mm will mean that the field of view is tiny making it hard to track objects. Also, higher magnification requires more light, so it will be dim on a small scope, and usually has a more limited range of eye relief, in other words, how carefully you have to move your head to just the right spot to see through it. Kellner, EP: I think these are kinds of eyepieces, defined by the stacking of convex and concave lenses. DSO: Deep space object. FOV: field of view 2": the larger of two standard eyepiece form factors