This lens is of superb quality and remembers me to the very good standard Zeiss lenses. Not absolutly perfect, but superb, better than the average lens. The colorcorrection is normal for a f12 achromat.
My rating stay about about 1/8 wavefront p.t.v and an strehlratio in the range of about 98%
Markus Ludes (APM-Telescopes)
Collimator : 9" F/9 Triplet Super ED TMB Apo / ronchi : 254 lines/inch or 100 lines/cm.