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 TS 2.5" flattener can be used on all refracting telescopes with focal ratios from f/5 to f/9. It has an M68x1 external thread and an M63x1 internal thread on the telescope side, ensuring maximum versatility. The required back focus of the refractor is at least 145 mm. This is the distance from the focuser to the focus. Almost all refractors offer this back focus.
TS Optics is a brand of Teleskop-Service.
