Astrograph with fast aperture ratio: A top-of-the-line model with outstanding performance and ease of use for visual observation and astrophotography!
The optical design of the objective, consisting of two SD lenses and one ED lens, delivers virtually aberration-free images. It produces sharp and beautiful star images that are uniform in quality right to the edges, regardless of whether you are taking pictures with a full-frame digital SLR camera or a larger 44 mm x 33 mm format camera. Enjoy the incredible performance of this lens, from high-magnification observation of planets to capturing deep sky objects in a relatively wide field of view.
The VSD90SS is particularly undemanding: even if you have neglected the focus a little, the result is round, sharp and beautiful stars across the entire image area. With the VSD90SS, beginners and professionals alike can fully exploit the possibilities of sky photography.
Astrographs produce optical vignetting, i.e. a gradual decrease in brightness towards the edge of the image, which is caused by the rear lenses being shadowed by the front lenses.
This edge darkening makes it necessary to process the image after exposure. To solve this problem, the VSD90SS uses large-aperture lenses in the rear elements and delivers over 90% of the light rays at the edge of the 60 mm image circle. Since the light intensity is uniform across the entire image field, you do not need to take edge darkening into account in image processing.
The VSD90SS features a large 87.5 mm diameter focuser to take full advantage of the large 60 mm image circle with excellent peripheral illumination. The focuser is versatile, including astrophotography with a large format or 35 mm full-frame DSLR camera or visual observation.
With a high-quality wide-angle eyepiece, you get sharp images of stars across the entire field of view during visual observation. In the centre of the field of view, a Strehl ratio of an impressive 96.7% is achieved at visual wavelengths. This Strehl ratio exceeds that of the SD81SII apochromat with 95.7%, which is known for its excellent optics.
It not only matters which telescope you buy but also where you buy it. Our additional services:
- We are a leading telescope dealer and know the devices we sell. Our customer service team will gladly help you after your purchase if you have problems with assembly or operation.
- We provide a copy of the 80-page Telescope ABC beginners handbook with every telescope.
