VISDRHDK

ES37245

Vixen Optics

The Vixen Optics SD Reducer HD Kit consists of a high-performance flattener lens, reducer lens, and connecting rings (Spacer Ring SD81, EX Tube 66) designed for prime focus astrophotography with the SD81S, SD103S and SD115S optical tubes. Used in combination with the Vixen SD Flattener HD (sold separately),the Reducer kit shortens the focal length by 0.79x (f/7.7 to f/6.1), while maintaining an image circle 44mm in diameter, largely improving sharpness over the entire imaging field of a DSLR camera with a full-format sensor. The SD Reducer HD can be used without the flattener on the AX103S and VC200L optical tube assemblies, and reduces focal length of both by 0.77x.Anti-Reflective Coating The same anti-reflective AS coating that is used for Vixen's high-end VSD 100 f/3.8 Astrograph is used on the Reducer HD, providing 99.9% light transmission. Loss of light, ghost, and flare are eliminated substantially due to the complete matte finish inside.Focal Length Reductions SD81S: 625-496mm (0.79x) f/7.7-f/6.1 with flattener and reducer; 625-644mm (1.03x) f/7.7-f/7.9 flattener only SD103S: 795-624mm (0.79x) f/7.7-f/6.1 with flattener and reducer; 795-811mm (1.02x) f/7.7-f/7.9 flattener only SD115S: 890-699mm (0.79x) f/7.7-f/6.1 with flattener and reducer; 890-908mm (1.02x) f/7.7-f/7.9 flattener only AX103S: 825-635mm (0.77x) f/8.0-f/6.2 VC200L: 1800-1386mm (0.77x) f/9.0-f/6.9