The Sharpstar f/4.4 Full-Frame Reducer for the 61EDPH-III is a dedicated corrector with a reducing power of 0.75x. It reduces the focal length of the 61EDPH-III to 270mm and the focal ratio to f/4.4.
This 4-element corrector delivers an illuminated and corrected field of 44mm, making the 61EDPH-III usable with full frame sensors. The working distance between the flattener and the sensor is 55mm.
The 61EDPH-III f/4.4 reducer can be connected to the focuser of the Sharpstar 61EDPH-III by using the M68 x 1 male thread. The camera side features the universal M48 x 0.75 male thread, allowing standard wide T-rings to be connected without the need for additional spacers. An internal M48 x 0.75 filter thread allows standard 2" filters to be used.
The reducer includes an M54 extension tube which can be removed in case extra backfocus is required. Without this, the resulting backfocus requirement becomes 75mm.