Optec NextGEN WideField 0.5x Telecompressor Reduction Lens (Requires CCD Mounting Plate)

The Optec NGW (Next Generation WideField) telecompressor increases the effectivespeed of the Meade and Celestron Schmidt-Cassegrain telescopes from f/10 to f/5. This 1/2 times reduction in focal length allows for 4 times greater field area and 1/4 reduction in exposure time for extended surface objects such as bright nebulae. The optical system comprises a set of 4 lens elements with two air spaces. All surfaces have a multi-layer broadband anti-reflection coating.

The system is optimized specifically for f/10 Schmidt-Cassegrain telescopes to allow for correction of the field curvature and spherical-chromatism that afflicts these types of instruments. At f/5, the maximum corrected field has a diameter of 17.5 mm at the image plane which makes the unit suitable for CCD cameras with imaging chips of the same diagonal dimension or smaller.