Wollensak Rapid Convertible 6 1/2 x 8 1/2

[Ole Tjugen]

I have aqiured an elderly lens, hoping to find some use for it on my equally elderly German "Reisekamera".

The lens is in a Regno shutter (which is slow, but works). There's a triple aperture scale for "10 1/2 EQ.", "18 BK" and "23 1/2 FT" which I take to be combined, rear and front element respectively. The aperture scales are the old US system running 8, 16, 32, 64 etc. I believe the 16 corresponds to f:16?

Counting the reflections I find four surfaces to each half, which confuses me a little...

Does anyone know anything more about this lens? Anastigmat or Rectilinear? Approximate age? Coverage?

Thanks.

[Ernest Purdum]

I think you have found an uncommon lens. I haven't found a reference to it after looking through quite a few sources covering Wollensak products of the time that the Uniform System was in use. (Most people other than Kodak had dropped it by 1910.)



By the lens name, I would have thought this to be a Rapid Rectilinear type, but the truly confusing four reflections rule this out.



You are correct in remembering that f16 is the same as U.S.16. U.S.1=f4, U.S.2=f5.6, U.S.4=f8, U.S.8=f11, U.S.16=f16, U.S.32=f22, U.S.64=f32, U.S. 128=f45.

[Ole Tjugen]

Checked again - no, there's definitely four. Two strong ones, one fainter moving in the opposite direction, and one which is difficult to see - when all three other reflections are centered, there's a "flash" reflection from the entire surface.

I'll have to put it on a camera then, to see what it's like . The main problem with that is that the mounting flange has "pinched" threads, so I'd liek to know a little more about it before I try to fix the threads. Which will probably then get even more damaged, so I'll need a new flange which would cost more than the lens did...

[Ernest Purdum]

It's tedious, and hard on the eyes, but "pinched" threads can usually be cleaned up with a "knife" shape needle file. I think the traditional steel types work better for this purpose than the diamond ones now on the market. Additional damage shouldn't be much of a hazard.