It is a 4 ” Maksutov-Cassegrain telescope combining the classic heritage of the original orange tube telescopes with the latest state-of-the-art features allowing a massive focal length of 1325mm in a sleek compact form.
This gives the Celestron Nexstar 4 SE a focal ratio of f/13 which combined give the Celestron NexStar 4 SE a high practical magnification limit of 240X – and when combined with the resolution factor of 1.36 arc seconds gives the telescope the ability to provide very good views of the lunar surface and very acceptable views of planetary details.