SD81S, SD103S, SD115S
The Vixen ED refractor range has been redesigned in order to allow the use of full frame DSLR camera sensors and yet are still compact and portable. The range is now designated SD (standing for Super extra low Dispersion glass) and includes the same 81mm, 103mm and 115mm variants.
Thanks to an improved baffle system, the incoming light near the edge of field of view has been increased when compared to the previous generation models.
The SD range now has its own dedicated field flattener and focal reducer. These help to deliver pin sharp star images across the field of view of a 35mm full-frame image sensor.
76146 SD81S
At only 625mm in length the SD81 is the smallest and most portable in Vixen’s new SD range. Perfect for observation and imaging on the move.
76147 SD103S
The SD lens in the SD103S gives excellent optical performance in a short optical tube for easy handling.
76148 SD115S
The largest aperture model of the SD series yet still compact at 940mm long and weighing under 5kg making it suitable for portable observation set-ups.
Shown with eyepieces sold separately.
The 60mm visual back on the ED range can accept either an optional extension tube or diagonal to accommodate 50.8mm (2”) eyepieces.
| Model | SD81S | SD103S | SD115S |
| Objective lens | 81mm ED apochromatic, multi-coated | 103mm ED apochromatic, multi-coated | 115mm ED apochromatic, multi-coated |
| Focal length (Focal ratio) | 625mm (f7.7) | 795mm (f7.7) | 890mm (f7.7) |
| Resolving power, limiting magnitude | 1.43 arc sec., 11.3 | 1.13 arc sec., 11.8 | 1.01 arc sec., 12.1 |
| Light gathering power | 134x | 134x | 270x |
| Tube size & weight | (OD) 90mm x (L) 585mm, 3.6kg (7.92lb) | (OD) 115mm x (L) 810mm, 5.4kg (11.89lb) | (OD) 125mm x (L) 930mm, 6.2kg (13.65lb) |
| Finderscope | XY red dot | 7x50 scope | 7x50 scope |
| Adapter thread / visual back | 60mm on scope body. 42mm for T-mount, 31.7mm push-fit, 50.8mm* push fit on included flip mirror | 60mm on scope body. 42mm for T-mount, 31.7mm push-fit, 50.8mm* push fit on included flip mirror | 60mm on scope body. 42mm for T-mount, 31.7mm push-fit, 50.8mm* push fit on included flip mirror |
| Accessories included | Dovetail adapter, tube rings, finder, carry handle | Dovetail adapter, tube rings, finder, carry handle | Dovetail adapter, tube rings, finder, carry handle |
| Photography** | Prime focus, eyepiece projection and afocal imaging | Prime focus, eyepiece projection and afocal imaging | Prime focus, eyepiece projection and afocal imaging |
*A 50.8mm mirror diagonal or a 50.8mm extension tube is needed to use a 50.8mm eyepiece.
**Optional photographic accessories are needed.
Optional Accessories
 |
77245 SD Reducer & Flattener HD Kit for SD scopes |
 |
77246 SD Flattener HD Kit for SD Scopes |
