The innovative wide and flat imaging field, that covers 645 medium format cameras, and e 5 elements in 5 group lens design completely eliminates a violet tint in chromatic aberration (blue halo). With an SD lens in the front objective group and an ED lens in the rear objective group, this scope achieves superb color correction. The blue halos around stars, that are visible in astrophotography and are hard to reduce with a 4 elements in 4 group lens design, are corrected successfully. In addition, astigmatism and coma aberrations are corrected to an extremely high level of image quality. The VSD 100 comes with an aluminum storage case.
The Strehl intensity on the lens design of the VSD100F3.8 is better than that on a 4 elements in 4 group lens design by approximately 10%. It does not decrease abruptly on stars away from the center of a photographic field. It is ideally suited to detect faint stars. The image circle is as large as 70mm in diameter (60% illuminated). The star images are as small as @ 15 microns around the corners, resulting in excellent field flatness.
The lenses of the VSD100F3.8 have the most up-to-date coatings of extremely high reflectivity. These have been developed to match the characteristics of each lens element in order to avoid the deterioration of image contrast due to the increase of lens elements. It boasts of a 99.9% light transmission at the maximum per lens surface and achieves superb images with extremely high contrast with no ghost and no flare images. (Patent pending). Astro Images on this page by Akio Nakanishi w/ K-16070M CCD Cooled. Click on each image for a larger view.