Caltar-II-N 150mm?

[Darin Boville]

I find the Caltar's a bit bewildering and for some reason am having trouble googling this--which Rodenstock lens is this?

Thanks!

--Darin

[Steve Goldstein]

Apo-Sironar-N

[Darin Boville]

Apo-Sironar-N

Thanks!

--Darin

[Oren Grad]

Strictly speaking, could be either Sironar-N or Apo-Sironar-N, depending on the vintage. Doesn't much matter, though.

[Ivan J. Eberle]

Reputed to be optically identical--with the same glass formulations-- whether APO designated or not. Ditto Caltar IIN versions.
I've also noted at the 150mm length, there is more of an image circle difference with the APO Sironar S version than the Sironar-N versions (AKA Caltar IIN) than there is at the 135mm length I prefer. (It's so quibbling at 135mm, and my Caltar IIN so sharp, that I've never whinged about not having an APO Sironar S. But maybe the differences are more significant at 150mm, can't say.)