This design bears my family name as it was designed by me. This is not a true "Catadioptric" design because the corrector plate is a neutral lens that does not change the direction of light rays passing through it. Unlike the previous Catadioptrics the main mirror is not spherical, but parabolic. The Neutral Corrector Plate really functions as a "Transparent Spider" holding the Secondary Mirror in place near the smaller end of the light cone. Flat optical surfaces are much more difficult to grind and polish than curved surfaces. Two flat surfaces perfectly parrallel is extremely difficult, - making this a premium design. With a true parabolic Main Mirror, and the Transparent Spider, this modification yields a coma free Newtonian with all the benefits and none of the shortcomings of that design.
Like the previous design, this one shares the ability to obtain Prime Image Photographs by removing the flat mirror and installing a CCD camera in its place.