0.77x Reducer/Flattener for Esprit 150DX (S20208)

34mm fully illuminated field, compatible with both APS-C and full frame sensors 89mm back-focus (55mm when back focus spacer and M48 ring installed) Drops f/ratio from native f/8 (1200mm) to f/6.2 (930mm) Reduces exposure time by 66% compared to native f/8 2.22 x 1.48-degree field of view when used with a full frame camera 1.45 x 0.97-degree field of view when used with APS-C crop sensor  Only compatible with Evostar 150DX focuser Includes reducer, metal thread-on caps, back focus spacer and M48 thread adapter Built-in 2" filter cell for mounting filters into light path