Fast 70mm high-performance astrograph F5.5 designed for demanding astrophotographers and observers, featuring 5 lens elements in 5 groups
With its sophisticated optical design incorporating five lens elements in five groups (Quintuplet), including two SD (Super ED) lenses and one ED (Extra-low Dispersion) lens, this astrograph delivers a virtually aberration-free optical system. The convex lens utilises two SD lenses and a high-refractive ED lens, while the front lens is crafted from a newly developed high-performance lanthanum glass.Perfect for astrophotography and visual observation
This revolutionary astrograph is compatible with digital full-frame DSLRs and even larger 44 x 33 mm cameras. With its fast F5.5 aperture ratio, the 70mm astrograph produces exceptionally sharp, high-contrast, pinpoint stars from the centre to the very edges of the field of view. Not only is it ideal for astrophotography, but it also excels in visual observation, offering a wide field of view for deep-sky objects and delivering stunning detail in planetary observation with high magnification.Consistently sharp imaging across the entire field
The VSD70ss is designed with a long peak range in focus adjustment accuracy, making it easier for astrophotographers to achieve consistently outstanding results. Even if the focus isn’t set perfectly, stars remain round and sharp across the entire image field.
The VSD70ss is very temperature-resistant so that you always keep a very stable focus point.Minimal vignetting for uniform illumination
Most astrographs experience some level of optical vignetting (light gradually diminishes towards the image edges). This is mainly caused by the rear lenses being shadowed by the front lenses. As a result, photographers often need to apply image corrections or capture additional flat frames beforehand. The VSD70ss tackles this issue with large-aperture lenses in the rear elements and preserves over 90% of the light all the way to the edge of its 55mm image circle. The result is uniform brightness across the entire field, eliminating the need for extensive post-processing to compensate for edge darkening.The VSD70ss features cutting-edge multi-coatings with exceptionally high reflectivity. These coatings have been specially designed to optimise the performance of each individual lens element, ensuring maximum contrast and light transmission without degradation across multiple lenses.Note:
*Mechanical vignetting may still occur depending on the camera system used, particularly due to the camera body or incorrect adapters.96.7% Strehl for stunning visual observations
When paired with a wide-angle eyepiece with low magnification the VSD70ss offers a flattened large field of view. Even with a high-quality wide-field eyepiece with a large field of view, stars appear sharp across the entire field of view during visual observation.
At the centre of the field, the telescope achieves an impressive 96.7% Strehl intensity at visible wavelengths—surpassing even the acclaimed SD81SII apochromat with its 95.7% Strehl ratio. This superior optical quality is also evident when observing the Moon and planets at high magnifications.Large, versatile, and stable focuser
The VSD70ss has a large focuser with a diameter of 87.5mm to make optimum use of the large 55mm field of illumination. Designed to support a wide range of accessories, this large focuser is perfect for astrophotography, accommodating everything up to large-format cameras or 35mm full-frame DSLR cameras. Its precision manufacturing ensures excellent stability, preventing any tilting even when using heavy imaging equipment.Optional VSD reducer for even faster results
The new reducer has been specially developed for the VSD90ss and the VSD70ss. At a focal ratio of 1:3.9. the photographer gets even faster results in astrophotography.Compatible with motorised focusers
To enable sensitive focusing, an optional dual-speed motor focuser is available for the VSD70ss.
Additionally, an EAF (Electronic Automatic Focuser) from ZWO or a compatible system can be retrofitted.

FEATURES

• SD apochromat, 5-element/5-group, AS coating
• Aperture: 70mm
• Focal length: 385mm (F/5.5)
• Resolution: 1.66
• Limiting magnification: 11.0
• Light gathering power: 100x more than the eye
• Field of view: 55mm
• Tube dimensions: 444 x 90 mm (368mm retracted)
• Adapters/Threads: 84mm (P=1mm), 60mm (P=0. 75mm), 42mm (P=0.75mm for T-ring)
• Connections: 60.2mm, 50.8mm, 31.7mm
• Weight: 3.5 kg

SCOPE OF DELIVERY

• VSD70ss Astrograph
• Adapter: 60.8mm to 50.2mm
• 1/4 inch screws (L: 9mm) x 2
• Allen keys (3mm, 2mm, 1.5mm, 3/16 inch)
• Dovetail bar (Vixen standard)