SVBONY M54x0.75 0.8x focal reducer and field flattener for refractor telescopes. After the focus is reduced, the starry sky can be captured wider, the star points are finer, and the signal-to-noise ratio is better under the same exposure. With advanced refractor, it can take dazzling celestial photos without worrying about the distortion of the star points on the edge of the photo. Multi-coated optics housed in a high polish, and hard anodize finished aluminum body to help reduce weight. The front end is a M54x0.75 socket to connect to the main lens, and the back end is M48x0.75 threaded to connect to the camera bayonet (Support Full Frame Camera).