“This is a triplet airspaced Super ED Apochromatic design which is fully multicoated. On todays market this represents the top of the line for 6" Apo’s. No other lens known to us comes close in terms of colorcorrection. The startest image show pure white diffraction at any power. The lenses are very smoothly polished and show an excellent spherical correction.
Markus Ludes (APM-Telescopes)
Note: these image where taken using a 10” MN as an autocollimator, therefore an artificial obstruction of 37% is visible.