Orion 08671 Eon Flat-Field Imaging 3" Field Flattener for Eon 115/130 EDT Refractors, Black

Boost the flat-field imaging performance of your eon Refractor with this handy field flattener. Designed for use with Orion eon 115mm and eon 130mm ED triplet APO refractors, the Orion 3" field flattener minimizes field curvature distortion that can otherwise elongate stars at the edge of the field-of-view. With the field-flattener installed, every exposure will exhibit track-sharp stars all the way to the edge of the imaging field. Fully multi-coated, two-element optics ensure maximum light transmission to preserve image brightness and clarity. Since the Orion field flattener for eon 115/130 edt refractors does not act as a reducer, it will not alter the focal length of the eon telescope it's used with. One side of the Orion 3" field flattener for eon edit refractors threads directly onto the 3" focuser of the eon 115mm or eon 130mm ED triplet telescope, while the other end features wide, M48 threads to reduce vignetting when used with DSLRs and other large-sensor cameras. This secure threaded connection ensures a rigid connection with zero flexure. The M48 threads are wider than standard M42 "t-threads" found on some other field flattener to minimize vignetting and provide better illumination of full frame camera sensors. Requires a compatible wide T-ring for use with DSLRs (sold separately). the 3" field flattener has a back focus, or flange focal distance, of 51.5mm, though it is known to be effective at up to 5mm on either side (46.5mm - 56.5mm). it adds 88.8mm of mechanical length to an imaging train. The Orion 3" field flattener for eon 115/130 ED triplet refractors weighs 1 lb., 2oz. Dust caps included.