F7 full format - for all Celestron Edge HD Optics
Celestron's new EdgeHD reducer offers a special five optical element (including lanthanum glass) design for EdgeHD telescopes, while maintaining the flat image field of EdgeHD optics.
In contrast to simpler reducers for the APS format, this HD Edge reducer does not shorten the original 146mm back focus. This means that not only all DSLR cameras can be connected, but also all the usual CCD cameras and filter wheels, active optic (AO) systems and off-axis guider adapters.
The 0.7X EdgeHD reducer include elements with extreme refractive indexes, including lanthanum elements with very low dispersion. As a result, the particularly high contrast of the Edge HD optics remains undiminished despite the many additional lens elements involved. There is no chromatic aberration over a very wide spectral range.
Every glass/air surface in this lens system is multi-coated to obtain maximum light transmission and colour fidelity. All lens edges have been meticulously blackened to completely suppress internal reflections. The large lenses, up to 60mm in diameter, allow a fully illuminated 42mm diameter image circle - suitable for large CCD sensors.
The intricately CNC-machined aluminum housing ensures exact spacing and proper alignment of lens elements. There is a metal screw cap to protect the lens from dust and damage when the Edge-HD reducer is not in use.
The f2 Hyperstar option and f7 Edge HD reducer turn the f10 Celestron EdgeHD Schmidt-Cassegrain optics into the most versatile telescope system in its price class.
