Use the Explore Scientific M48 x 0.75 Extension Ring Set for setting different distances from your imaging camera to the focal plane of your telescope or corrector/field flattener to achieve proper back spacing during astrophotography. This is ideal when you set up your imaging system for the first time, if you use different imaging systems on the same OTA, or use different OTAs with the same imaging system.

The set consists of five rings—30, 20, 15, 10, and 5mm—with large 45mm inner diameters that help to prevent undesired vignetting of the camera sensor. There are internal and external M48 x 0.75 threads on in each individual tube that allow them to be stacked into different lengths, and the threads are compatible with large T2 photo threads or 2" filter threads for use with camera-specific bayonet adapters or filters without converter adapters.