The Vixen VSD 100 Astrograph offers a wide and flat imaging field that covers 645 medium format cameras. The 4" optical set is a 5 element /5 group design that completely eliminates the violet tint in chromatic aberration (blue halo). With an SD lens in the front objective group and an ED lens in the rear objective group, this telescope achieves superb color correction. Blue halos around stars that are visible in astrophotography are hard to reduce, even with a 4 elements in 4 group lens design, but in the VSD design they are corrected successfully. In addition, astigmatism and coma aberrations are corrected to an extremely high level of image quality. The Strehl intensity on the lens design of the VSD100 f/3.8 is better than that on a 4 elements in 4 group lens design by approximately 10%. It does not decrease abruptly on stars away from the center of a photographic field. It is ideally suited to detecting faint stars. The image circle is as large as 70mm in diameter (60% illuminated). The star images are as small as @ 15 microns around the corners, resulting in excellent field flatness.
The lenses of the Vixen VSD 100 f/3.8 Astrograph have the most up-to-date coatings of extremely high reflectivity. These have been developed to match the characteristics of each lens element in order to avoid the deterioration of image contrast due to the increase of lens elements. It boasts of a 99.9% light transmission at the maximum per lens surface and achieves superb images with extremely high contrast with no ghost and no flare images.
Tony Hallas says: "To have this level of performance from an f/3.8 is remarkable. All in all..a very impressive little telescope! The telescope is essentially sensational. It accomplishes the impossible. Mechanically superb as well, supporting the heavy 16803 camera without any complaint and the enormous helical focuser is tight and accurate. With extremely fast optics, flat field, and superb color correction it is a unique product not just a rehash of the same."
In the process of manufacturing optical glass, all the five lens elements are annealed with a precision annealing process. The annealing can straighten molecular arrangements of lens elements and thus unify the characteristic of optical glass. The homogeneity of refractivity in optical glass is enhanced to the highest degree.
The Vixen VSD 100 f/3.8 Refractor has an oversized focuser that can be attached to the 645 medium format cameras without difficulty. Highly accurate focusing is possible with the non-rotational helical fine focuser, where the distance of drawing in and out the focuser can be read as small as 20 microns with the provided vernier scale. All the graduations are engraved. The Vixen VSD 100 also comes with an aluminum storage case.
- Vixen VSD 100 Refractor Astrograph
- Aluminum Case
- Lens Cap
- Allen Wrench
Dimensions & Specifications
SD Apochromatic Refractor
Five, with 1 SD and 1 ED
Focuser Drawtube Diameter:
Focuser Adapter Thread Diameter:
M84 pitch 1 mm, M60 pitch 0.75 mm, M42 pitch 0.75 mm
Focuser Push Fit:
60.2 mm, 31.7 mm
Focuser Filter Thread Diameter:
1.16 arc seconds
Light Gathering Power:
115 mm (Requires VSD 115 mm Tube Ring)
Rings, sold separately
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Default manufacturer warranty.
Return & Exchange Policy
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