I have and use a 508mm f/7 Calumet Caltar ILEX lens in a No. 5 Universal Shutter on my 11x14. I have seen FS a 508mm f/7 ILEX Acutar and an ILEX 508mm f/7 Paragon in the same shutter. In the 1970s, I once owned a 508mm ILEX with a very, very low serial number. I assume that that one was of the first 508mm's and sold directly by ILEX. So obviously ILEX made all these lenses, and Calumet distributed them as Caltars. I was wondering who distributed Acutars and Paragons?

I read that Linhof sold only the top of the line Schneider lenses... am I right on that Bob? Or did Linhof just test its Schneider lenses before labeling them "Linhof"?

Was there any difference between Acutars, Caltars, and Paragons? To me seems that labeling the front of the lenses with the different brands, just occurred on the ILEX manufacturing line, and they were all just assumed to be optically equal... dangerous assumption. In the 1990s acquired a 24-120mm AF Nikkor. Was able to try out 5 or 6 samples of this optic, one stood out amazingly better than the other samples and bought it in an instant... to this day is one of the sharpest Nikkors that I own and use.

Just curious....