Focal reducer and field flattener for Vixen Super ED 81mm, 103mm and 115mm SD series apochromat refractors
Vixen's new and outstanding flattener and reducer kit consists of the high performance flattener lens and reducer lens designed for prime focus astrophotography with the SD81S, SD103S and SD115S apochromat refractors and boast extraordinary enhancing, flat-field performance while reducing the focal length by 0.79x.
The SD flattener HD improves the flat-field performance toward the edge of field of view closely maintaining the original focal length of the SD-series optical tubes, fully covering the imaging field of DSLR camera with full-format sensor at image circle of 44mm diameter.
Using in combination with the supplied Reducer HD, the focal length will be reduced by 0.79x (F7.7?6.1), while maintaining image circle in dia. 44mm, largely improving sharpness over the entire imaging field of the DSLR camera with full-format sensor.
Extraordinary High Contrast
The same anti-reflective AS coatings, which are used for the high-end VSD100F3.8 Astrograph are used to take advantage of 99.9% superb high transmission of light per lens surface. Loss of light, ghost and flare images are eliminated substantilly due to the complete matte finish inside.