about a K and F company lens

[jeff c.]

I have just aquired a lens- All it says is K and F. company Chicago 235. Aperture range is 12.5 to 90. Can someone give some info about how I could use this lens or its worth. Thanks, Jeff

[Ted Harris]

Here's a wild guess. It's not K&F but K&E standing for Keuffel + Esser the permier US manufactuerer of a wide range of engineering and surveying instruments from 1867 onward. The part that doesn't fit is that they are in New York not Chicago.

[Jim Galli]

Wild guess but f12.5 indicates perhaps it was the matching "wide field" lens to the Protar you also asked about. Early Wide Angle offerings like Perigon and Wollensak and others I'm not thinking of just now had f12.5 max apertures. If it was the wide angle to complement that Protar it might focus at around 8" for 8X10. Lots of wild speculation here.