For NexStar 4 and for all C90 Spending with these Celestron T adapters, small image reflex cameras (35mm) can be connected in the primary focus of the Nexstar 4 or the C90 perspective. In this way, you can photograph terrestrically but also take moon and planet recordings. For Deep Sky Photography you need an additional key scope. In addition to the T adapters, a T-ring is required for the respective camera.