The flattener is a lens that evens out the field, as this is slightly curved by the primary optics. This curvature causes stars that are imaged at the edge of the field of view to be less sharp. The flattener, also called a field flattener, corrects this effect. Astrophotographers can then enjoy images where the stars remain sharp right out to the edge of the exposure. The flattener is installed between the telescope and the camera.
The flattener adopts an air-spaced triplet structure, the peripheral light reduction control is excellent, can effectively improve the curvature of the field, improve the corner image quality, and reduce aberrations, so that users can take clearer astronomical photos.
One end of the flattener features an M68×1 female thread to connect to the focuser drawtube, the other end of the flattener has an M48×0.75 male thread with built-in 2" filter thread. The back focus is 55 mm. If it needs to be extended, the flattener can be split to reveal an M54×0.75 female thread, and the back focus becomes 81.5 mm.
