The Vixen Optics SD Reducer HD Kit for Telescopesconsists 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.

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.

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

Related Questions and Answers

Q: 1. What is the inside diameter of the shaft that fastens around the mount? I need 1/4" ID.

A: This model fits a 1/4 inch shaft, so this will work with what you have.

Q: 2. What is the back focus distance of this reducer?

A: With the focal reducer, it is 63.5mm.

Q: 3. I have a Canon T6s with a 500mm telephoto lens and 2X Lens on that. Will the Vixen Optics 3562 Piggyback Fine Adjustment Unit DX support this? What is the actual weight limit?

A: I do not recommend using this for your set up. It won't be sturdy enough from what it's showing. The head is only 12oz, so I really don't think this will work. My apologies.

Q: 4. Vixen Optics H4x16 ArtScope ㅛYou answered. "Monocular is about 3.5 inches long and 2 inches in diameter." How about the weight?

A: The Vixen Optics H4x16 ArtScope Monocular (Blue) Weighs 49g (1.7oz).

Q: 5. CAN I TAKE PICTURES BY CONNECTING MY CAMERA?

A: Yes you can, but you would need adapters to do so. I would need to know what camera model you have to make the proper adapter recommendations.

Q: 6. Is it possible to remove the cross hairs?

A: The Vixen Optics 100mm Finder Eyepiece does not allow for the cross hair reticle to be removed.

Q: 7. Is this compatible with Vixen SXD2 mount?

A: Yes, the Vixen Optics eSG Half Pillar is compatible with the Vixen-Sphinx-SXD2 mount

Q: 8. Will this fit one of the old Vixen Polaris mounts as well? What is the length and threading of the bolt?

A: Unfortunately it will only fit the current Advanced clamp. If you need a replacement lever for your older mount I would recommend that you contact Vixen directly.

Q: 9. What is the eye relief?

A: The MFR only provides this info, please contact them directly for the Eye relief. Reduce the need for a finder scope with this lower power eyepiece. Fits 31.7mm visual back. Contains cross hairs. Focal length: 100mm Apparent FOV: About 11 Degrees Size: 2" x 7.3" Weight: 6.35 oz Actual field of view varies with optical instrument. Examples of actual field of view: Vixen SD81 OTA with a focal length of 600mm is 1.76 degrees SD103 OTA with a focal length of 795mm is 1.38 degrees SD115 OTA with a focal length of 890mm is 1.23 degrees VMC200lL with a focal length of 1950mm is 0.56 degrees Vixen Optics Tel: 949-429-6363 Email: support@vixenoptics.com Website: http://www.vixenoptics.com/

Q: 10. Can the Vixen Mobile Porta Mount separate from the tripod and be used on other tripods?

A: Yes, the Vixen Optics Mobile Porta AZ Mount with Tripod can have the head removed from the tripod.