The independently-researched Sharpstar 121SDQ is a high-quality astrograph featuring quintuplet air-spaced APO objective lens design. The lens set can be further divided into two separate groups. The first group contains three lenses and one of which is an ED(extra-low dispersion) glass. This configuration can greatly enhance its performance in astrophotograph. The image circle can be acceptably extended to 60mm, effectively controlling the vignette at the edge of the images. It’s especially preferred by most experienced astrophotographers.
Sharpstar 121SDQ considerately takes the back-focus into account, as it is an essential specification in sky-imaging. Sharpstar 121SDQ provides 145mm working distance which accommodates the attachment of most advanced and sophisticated imaging devices.
The pioneering 4" large-size focuser is tapped with different thread types which is of great convenience for users to attach potential accessories with the help of proper adapters. The artistic appearance and functional utility make the Sharpstar 121SDQ quite a superb astrograph.
Taken with Sharpstar 121SDQ, RGB filter 8×300s respectively, L2 filter 2×300s
Taken with Sharpstar 121SDQ, RGB filter 10×300s respectively, L6 filter 6×300s