Any experience of Petri 1.8/55?

[RLangham]

Flint and Crown glass are glass families and most photo lenses use glasses from both families. There are very cheap flint glasses and expensive flint glasses.

As for petri lenses, what i've read on the net is often glowing reviews for the lenses on their RFs and the lenses for their classic (big) SLRs. So they were supposedly good at making lenses, or another good OEM (like Tomioka or Kowa) made them.

I would assume that as a telescope manufacturer they'd make their own. Something about the feeble attempt to market their lenses based on meaningless facts about the optics screams that photography was an afterthought to them.