Optec Lepus 0.62x Telecompressor Lens for Celestron 8", 9.25", and 11" EdgeHDs
Optec Lepus 0.62x Telecompressor Lens for Celestron 8", 9.25", and 11" EdgeHDs
This Optec 0.62x 4-element Telecompressor lens is compatible with Celestron 8", 9.25", and 11" EdgeHD telescopes. The Lepus SCT also works as a focal reducer and provides 0.62x reduction of the effective focal length of the telescope. Users can pair the Lepus SCT with most mid-size CCD cameras and digital SLR cameras that have a sensor diagonal up to 28 mm.
Telescompressor lenses correct coma that is inherent in the classic SCT, and this specific lens is designed so that it doesn't overcorrect the already corrected EdgeHD optics. Optec has designed the telecompressor with a back focus of 105 mm that is achieved without adapters. Also included is an M42 adapter to achieve 55 mm of back focus. On the telescope side of the telecompressor lens, there are female SCT threads that screw onto the rear cell of the scope. The camera side has male SCT threads that will facilitate the connection to the appropriate EdgeHD T-adapters or threaded SCT diagonals. Additional adapters are required to connect to M48 threaded adapters.
The Lepus SCT is optimized for 100 mm of distance between the image plane and the last lens surface. The Celestron 9.25" EdgeHD is an exclusion when it comes to the 100 mm distance. When the image plane is shifted outward, it will provide more reduction, but there would be a loss of star quality at the edge of the images.
Optec has designed the Optec Lepus SCT so that it can deliver a fully unvignetted image with a 22 mm diameter, though it can also provide well-corrected images out to 28 mm with a little light fall-off. Flat fielding is recommended for the best results possible.
