Two factors determine the true field: the telescope's focal length and the diameter of the eyepiece's field stop. A field stop is a centered, circular opening in front of the eyepiece's front (or ...

THE PERFECT ALL-IN-ONE EYEPIECE AND FILTER KIT: See more with your telescope! This expertly curated kit features the most popular 1.25" telescope eyepieces and filters, plus a 2x Barlow lens.

Refractor telescopes have long optical tubes as light travels in a straight line to the eyepiece. Compared to premium telescopes used by photography experts, refractors are generally more portable.