Vixen SD Reducer HD focal reducer for Vixen AX103S and Vixen VC200L Visac

Vixen SD Reducer HD

The Vixen SD Reducer HD is an aplanatic focal reducer desigend to work with Vixen AX103S astrograph and Vixen VC200L Visac catadioptric. When used together the Vixen SD Flattener HD it can be used also onto Vixen SD optics. It delivers high contrast flat field over an imaging circle up to 44 mm, perfect also for full frame (24x36 mm) CCD/CMOS sensor.

Vixen AS Coating

All the new high performance correctors by Vixen include the highly renowned Vixen AS Coating that ensures over 99.9% light transmission for each optical surface. It is the same coating used also in the Vixen flagship VSD 5-lens astrograph. This advanced coating enhances contrast and cuts down to a negligible effect any possibile loss of light and any ghost or flare image.

SD Reducer HD specifications

SD Flattener HD + SD Reducer HD specifications

*1 : Over 60% is considered an acceptable value in photography. Field correction covers an imaging field of 44 mm so bigh enough to cover the full-frame APS format (24 x 36 mm) and much higher than APS-C format (28.8 mm).

*2 : Field correction covers a diameter 44 mm, but at the edge you will get a 47% illumination only. So we reccomend sensors up to 36 mm diameters, corresponding to the APS-H format.

SD Reducer HD spot diagrams onto Vixen AX103S astrograph

The Vixen AX103S astrograph is natuvely corrected up to full-frame 24x36 mm format, but the former 0.7x reducer has been designed for sensor up to APS-C format. Now the new SD Reducer HD covers also the full-frame format, although reduction is a little bit lower (F/6.2 vs. F/5.6).

Vixen AX103S spot diagrams at prime focus (F/8)

Vixen AX103S spot diagrams at prime focus with SD Reducer HD reducer (F/6.2)

Vixen AX103S spot diagrams at prime focus with #VX-37228 0.7x designed for APS-C sensors (F/5.6)

SD Reducer HD spot diagrams onto Vixen VC200L "Visac" catadioptric

The Vixen VC200L Visac catadioptric is well known as a great imaging performer also on big sensors. Performances were good also with the former 0.71x focal reducer, expecially with sensors up to APS-C format, but now with the new SD Reducer HD focal reducer you can have an even better field correction over a 44 mm image circle, although we reccommend sensor up to 36 mm image circle because of vignetting at the edge. Field illumination at the edge of the 36 mm image circle is 60%, and only 47% at the edge of the 44 mm image circle.

Vixen VC200L spot diagrams at prime focus

Vixen VC200L spot diagrams at prime focus with SD Reducer HD installed (F/6.9)

Vixen VC200L spot diagrams at prime focus with #VX-37229 0.71x focal reducer installed (F/6.4)

Vixen SD Spot diagrams

Vixen SD103S spot diagrams at prime focus without correctors (F/7.7)

Vixen SD103S spot diagrams at prime focus with SD Flattener HD field flattener and SD Reducer HD focal reducer (F/6.1)

Example images

The M8 and M20 nebuale in Sagittarius taken with Vixen AX103S astrograph and SD Reducer HD

M101, the Pinwheel Galaxy, taken with Vixen VC200L Visac astrograph and SD Reducer HD focal reducer

The M31 galaxy taken with Vixen SD103S and SD Flattener HD field flattener + SD Reducer HD focal reducer

System Chart