By using the Celestron 0.7x reducer/corrector, the EdgeHD 800 changes from f/10 to f/7, making deep-sky long exposure astrophotography (for objects like galaxies , nebulae and star clusters) much easier. The optical system consists of 4 elements with Lanthanum lenses that ensure crisp and sharp images minimizing chromatic aberrations. All lens edges are blackened to minimize unwanted reflections and increase contrast.
The Celestron 0.7x reducer/corrector for EdgeHD 800 provides a larger field of view by 43 % compared to the native of the telescope focal length and allows the use of sensors with diagonal up to 35mm like DSLR or large-format CCD sensors camera, without causing vignetting and keeping the flat field native of Edge HD optics.
The back focus is 105mm, it means that, in order to ensure the best performance, the sensor must be placed at 105mm away from the reducer thread. The installation is very simple, just screw the focal reducer instead of telescope visual-back, then thread the optional T- Adapter for EdgeHD 800, the camera side T2 thread allows to install any DSLR or CCD camera to the telescope. It will provide also the correct working distance. The T2 ring (not provided) will let you connect any DSLR or CCD .