Astrophysics visual back

This 2-inch Visual Back threads onto the rear cell of Celestron 11-inch to 14-inch SCTs with 3

29-inch male threads on the telescope's rear cell

It provides a full 2-inches of unobstructed opening (unlike most visual backs)

A Visual Back is a metal adapter that screws onto the standard rear cell threads of Schmidt-Cassegrain and Maksutov-Cassegrain telescopes and accepts 1

25” accessories, including diagonals, eyepieces (for straight-through viewing), Barlows, webcams, and any other accessory with a 1

The back focus is the distance between the back of the telescope and the focal plane, i

, how far back the telescope+flattener will focus the image

This is a critical parameter in astrophotography

In order to be able to focus with your camera, the camera sensor must be placed at the proper distance from the back of the instrument