New APO refractor from Vixen: SD103SII released

Vixen has introduced the SD103SII Optical Tube Assembly, an upgraded apochromatic refractor designed for both visual observation and astrophotography. Priced at $2141.99, this new model promises superior performance and stunning star images.

Introducing the new Vixen SD103SII APO refractor

The SD103SII, a worthy successor to the SD103S, is part of Vixen's SD series of apochromatic refractors. Featuring a 103mm aperture and a 795mm focal length, this optical tube is designed for versatile use, from visual observation to astrophotography. Vixen has replaced the three-piece foil fragment spacers around the objective lens with a ring-shaped spacer to ensure uniform diffraction light, resulting in more beautiful star images. When paired with the optional SD Flattener HD Kit and SD Reducer HD Kit, the telescope transforms into a high-performance astrograph, offering a 44mm image circle perfect for full-frame DSLR and CMOS cameras.

High-performance SD glass lens that suppresses color fringing

In the previous SD103S model, small tin foil fragments were used as spacers at three points around the lens. These fragments protruded into the effective aperture, causing diffraction that resulted in radial breaks around the star images. By replacing these fragments with a ring-shaped spacer, the SD103SII ensures uniform diffraction light, producing clearer and more aesthetically pleasing star images.

The SD103SII addresses chromatic aberration, a common issue in refractors caused by the varying refractive indices of different wavelengths of light. Using an SD glass (Super ED) lens made from FPL53 glass, which has superior optical performance among ED glasses, the telescope significantly reduces chromatic aberration. This results in sharper and clearer star images across all visible colors, with particularly noticeable improvements in the short-wavelength g-ray (purple).

With a 103mm aperture and a 795mm focal length, the SD103SII is versatile, suitable for a range of uses from planetary observations to photographing nebulae and star clusters. The supplied flip mirror diagonal allows quick switching between straight-through and vertical optical paths, and two eyepieces of different magnifications can be used interchangeably. Users can easily switch between visual observation and photography by attaching a camera on one side and an eyepiece on the other. The telescope's standard dovetail attachment plate and metal carry handle facilitate easy mounting and transport.

When paired with the optional SD Reducer HD Kit and SD Flattener HD Kit, the SD103SII becomes a high-performance astrograph, ideal for high-quality astrophotography with full-frame DSLR or CMOS cameras.

Additionally, the telescope comes with a 7x50mm finder scope with an illuminated reticle, featuring crosshairs and adjustable red illumination for easy sighting in dark conditions. The detachable eyepiece unit with a 31.7mm sleeve allows the finder scope to double as a guide scope when replaced with a compatible CMOS camera.

Vixen Telescope SD103SII OTA highlights

• Innovative Spacer Ring Design: The SD103SII introduces a ring-shaped spacer, replacing the previous three-piece foil fragments. This new design minimizes diffraction around star images, resulting in cleaner and more beautiful visuals. The uniform diffraction light provided by the ring-shaped spacer ensures sharper and clearer star images.
• High-Performance SD Glass Lens: The SD103SII features a high-performance SD glass (Super ED) lens made from FPL53 glass, known for its excellent optical qualities. This lens effectively suppresses chromatic aberration, a common issue where different wavelengths of light refract at different angles, causing color fringing. The SD glass minimizes this effect across all visible wavelengths, particularly the short-wavelength g-ray (purple), producing crisp and clear star images.
• Versatile Design for Multiple Uses: With a focal length of 795mm and an aperture of 103mm, the SD103SII is designed for versatility, making it ideal for planetary observations and photographing nebulae and star clusters. The supplied flip mirror diagonal allows users to quickly switch between visual observation and photography, enhancing the telescope's usability for various applications.
• Optimized for Full-Frame DSLR and CMOS Cameras: The SD103SII is compatible with full-frame DSLR cameras and CMOS cameras. When paired with the optional SD Flattener HD Kit and SD Reducer HD Kit, the telescope transforms into a high-performance astrograph, providing a 44mm image circle suitable for full-frame imaging sensors. This ensures high-quality astrophotographs with minimal distortion.
• 7x50mm Finder II with Illuminated Reticle: The finder scope has crosshairs and adjustable brightness for easy sighting in dark fields. The detachable eyepiece unit can be replaced with a commercially available CMOS camera, allowing the finder scope to double as a guide scope.
   

SD103SII Optical Tube Assembly specs

• Objective lens, effective aperture: 103mm / SD apochromat, multi-coated SD(Super ED)glass lenses
• Focal length (F ratio): 795mm(F7.7)
• Resolving power, limiting magnitude: 1.13 arc seconds, 11.8
• Light gathering power: 217x unaided eye
• Focusing mechanism: Rack-and-pinion, with lock knob
• Adapter thread / Visual back: 60mm and 42mm for T-ring / 50.8mm and 31.7mm push fit with flip mirror diagonal
• Finder scope: 7x50mm Finder II, dark field illumination, 7 degrees field of view
• Accessories: Tube rings, dovetail attachment plate, metal carry handle
• Dimensions / weight: 115mm O.D. x 810mm long, 5.5kg (Net 3.6kg)
• Photography: Usable with eyepiece projection, prime focus, afocal imaging
• Solar observation: Available with optional Sun projection screen set B
• Optional: 50.8mm eyepiece adapter is needed. A camera adapter fitting to your camera is separately needed.
   

Optional accessories: 

• SD Reducer HD Kit: Includes a flattener lens, reducer lens, and connection ring, improving photographic performance and reducing focal length by approximately 0.79 times.
• Wide Photo Adapter 60DX: Camera adapters for prime focus astrophotography, available for Canon EOS (EF mount) and Nikon (F mount), reduce vignetting and enhance durability.
• Dual Speed Focuser: Allows coarse and fine focus adjustments, essential for high-magnification observations and astrophotography.
   

Enhance your astrophotography with the SD Reducer HD Kit and SD Flattener HD Kit