How to reach the 55mm back focal length with ASI cameras? The back focal length is advised by the telescope manufacturers. Since most telescopes have 55mm back focal length, we are providing the detailed guidelines for all our cooled cameras. Please be noted that these are just examples for 55mm back focal length, you need to know the back focal length of your reducer and flattener first and then arrange the adapters. Notice: About small format, 174, 178, 385, 290, 224, 185, etc. The package does not include some adapters, please take a look […]