The startest shows a very smooth surface, maybe not as clear in the image as at the eyepiece (300 power). The optics are free of visible zonal deffects. The colorcorrection for such a fast doublet SD is very good with a hint of violet at highest power on brighter stars.
My personal rating on this optic are about ~ 1/7 wavefront p.t.v. and in the area of about ~ 97% strehlratio. A real interf. test could show some slightly diffrent results, in any case its an very good optics
Markus Ludes (APM-Telescopes)