Vixen VC200L Aspherical Cassegrain OTA with Reducer HD 0.79x focal reducer
Kit composed by the Vixen VC200L Aspherical Cassegrain OTA and the Reducer HD 0.79x focal reducer. High-performance system suitable for modern large-size CCD and CMOS sensors with tiny pixels.
Contact us for info about connecting your DSLR or your CCD / CMOS cameras.
Vixen VC200L Aspherical Cassegrain OTA with accessories
The Vixen VC200L is 20 cm F/9 modified Cassegrain OTA. The Vixen VC200L's catadioptric VISAC (Vixen Sixth-Order Aspheric Cassegrain) optical system is one of the most sophisticated optical designs available on the market today: free of coma, curvature of field, spherical and chromatic aberration. Especially noteworthy in the Vixen VC200L is its sharpness and flatness at the edge, which far exceeds that of Schmidt-Cassegrain systems of the same aperture. It provides a pinpoint star image less than 15 microns, even at the edge of its 42 mm image circle. If you are looking for a photographic catadioptric, the Vixen VC200L is an excellent choice.
The Vixen VC200L telescope features the VISAC optical system. The VISAC optical system is composed of a concave primary mirror, a convex secondary mirror and a three-element field corrector at the base of the focuser. The primary mirror is a unique innovation: a precise sixth-order shape produced by Vixen's High-Precision Poly-Order Aspherical Mirror Molding Technique.
The Vixen VC200L is well suited for observation and astrophotography of the moon, planets, star clusters, nebulae, and comets. The rack-and-pinion focusing mount accepts optional 2-inch eyepieces and accessories, and an f/6.4 reducer for photographic use is also available. The open tube design of the Vixen VC200L eliminates the dew problem that is common with conventional Schmidt- or Maksutov-Cassegrain systems and its size makes it very easy to handle. The new white VC200L telescope has a lighter-weight optical tube with improved anti reflection coatings, a metal carrying handle and now comes standard with a 7x50 mm finderscope.
"The focuser with which the VISAC is fitted is simply wonderful. It is an independent rack & pinion model mounted behind the primary, which remains stationary. Most Schmidt-Cassegrains suffer from mirror shift, to one degree or another. Companies have done their best to minimize this common issue, but it is still present in the many models I've tested. The typical Schmidt-Cassegrain is focused by moving the primary optic back and forth, in effect changing the focal length of the optical train to match the location of the imaging sensor or eyepiece focal point, rather than moving those elements to a fixed focal point. This mirror shift can sometimes cause target objects to shift on the focus plane during focus and can be quite troublesome while imaging deep sky objects. Because the VISAC primary stays stationary, mirror shift induced image shift is essentially eliminated. Another interesting feature is the VISAC's metal side plate which runs along one side of the dovetail plate. This brilliant idea prevents the clamp screws of the saddle plate from marring the dovetail plate and should be incorporated on other designs. Another nice feature is a carrying handle located on top of the OTA. This proved to be very useful when lifting the optical tube on and off the mount. Overall, the visual image quality of the VISAC was quite impressive, particularly considering how portable and light weight it is. It is a step up in image quality from the typical Schmidt-Cassegrain in my opinion, particularly with regard to edge sharpness. Although the VISAC costs nearly double what an 8-inch Schmidt-Cassegrain optical tube does, I think it's worth it!" - Daniel Mounsey, "Astronomy Technology Today".Features
- Optical Tube Dimensions of 620 mm x 232 mm length x diameter and weight of only 6 kg for exceptional portability.
- Limiting Visual Magnitude of 13.3 and outstanding Theoretical Resolution factor of 0.58".
- Primary mirror is held by a retaining ring, instead of hooks to decrease flare and enhance contrast.
- Lighter weight optical tube and improved anti-reflection coatings.
- High-definition star images to the edge of a wide viewing field and offers exceptionally outstanding performance in astrophotography.
- Excellent image correction throughout the large illuminated field (42 mm diameter fully illuminated).
| Optical design |
Vixen 6th-order apsherical Cassegrain | |
| Diameter | 200 mm | |
| Focal length |
1800 mm | |
| Focal ratio |
F/9 | |
| Backfocus |
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|
| Limiting magnitude |
13.3 | |
| Resolving power |
0.58" | |
| OTA diameter |
232 mm | |
| OTA length |
620 mm | |
| Weight | 6 Kg | |
| Focuser | Rack & Pinion, 60 mm thread | |
| Included accessories |
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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
| Optical tube | AX103S / VC200L |
|---|---|
| Focal length | 825 mm / 1800 mm |
| Magnfication | 0,77x |
| Resulting focal length | 635 mm / 1386 mm |
| Focal ratio | F/6,2 / F/6,9 |
| Image circle *1 | 44 mm / 36 mm *2 |
| Peripheral illumination | 63% / 60% |
| Optical design | 2 elements in 2 groups |
| Coating | Vixen AS Coating (over 99,9% light transmission for each lens surface) |
| Dimensions / Weight | 68 x 45.2 mm / 218 g |
SD Flattener HD + SD Reducer HD specifications
| Optical tube | SD81S / SD103S / SD115S |
|---|---|
| Focal length | 625 mm / 795 mm / 890 mm |
| Magnfication | 0,79x |
| Resulting focal length | 496 mm / 624 mm / 699 mm |
| Focal ratio | F/6.1 |
| Image circle *1 | 44 mm |
| Peripheral illumination | 72% / 63% / 60% |
| Optical design | 2 elements in 1 group + 2 elements in 2 group |
| Coating | Vixen AS Coating (over 99,9% light transmission for each lens surface) |
*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)
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Vixen AX103S spot diagrams at prime focus with SD Reducer HD reducer (F/6.2)
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Vixen AX103S spot diagrams at prime focus with #VX-37228 0.7x designed for APS-C sensors (F/5.6)
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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
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Vixen VC200L spot diagrams at prime focus with SD Reducer HD installed (F/6.9)
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Vixen VC200L spot diagrams at prime focus with #VX-37229 0.71x focal reducer installed (F/6.4)
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Vixen SD Spot diagrams
Vixen SD103S spot diagrams at prime focus without correctors (F/7.7)
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Vixen SD103S spot diagrams at prime focus with SD Flattener HD field flattener and SD Reducer HD focal reducer (F/6.1)
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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
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System Chart
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DATA SHEET
| Product Status | New |
|---|---|
| Package width | 40 cm |
| Package height | 34 cm |
| Package depth | 70 cm |
| No. of parcels | 1 |