Re: 508mm f/7 ILEX lenses
Chauncey, USAF used a 20"/5.6 B&L tele on I-know-not-which 35 mm camera. If the data sheet is to be believed it was poorly achromatized, had high resolution.
But the cross-section looks like a classic tele with a cemented doublet at each end of the tube. Short back focus, ~ 5" at infinity.
Re: 508mm f/7 ILEX lenses
I have one of the f/5.6 teles, salvaged from an estate lot, where it was installed on a Leica III with mirror box (!).
No shutter of course but holding it up to 8x10 it seemed to at least illuminate the GG fully. One of these days I'll get it on a camera (I have a Packard shutter I've never used). Should be fun, at the least.
There's some info online about them if you search, mostly similar stories of "got it cheap, haven't used it."
Re: 508mm f/7 ILEX lenses
Dan, thanks for the info. This one weighs a little over four and a half pounds and the back focus is about 12 to 14 inches so might be a bit much for a 35;-) It probably is military though in spite of its full commercial looking info "BAUSCH & LOMB OPT. CO. ROCHESTER, N.Y., U.S.A. TELEPHOTO ANASTIGMAT FOCAL LENGTH 20 INCH (508MM) F/5.6 and then the serial. Has a military sounding serial VFxxxxRm and has some posts on both the inner and outer sides of the "hood" for filters of some kind. f/5.6 to f/45 with a nice circular 20 bladed diaphragm. Maybe a 4x5 roll aerial camera but no way to automate the aperture so would have to be hand set. Guess I'll have to shoot it to see.
Re: 508mm f/7 ILEX lenses
Well, the posts make it a lens for an aerial camera. They accept a spring-loaded filter holder that won't vibrate off.
Re: 508mm f/7 ILEX lenses
I have two of these 508mm Ilex-Calumet Caltars. one with serial number in the one hundreds and one in the four thousands. While there are superficial differences in the Universal Synchro shutter's knurled ring, the lenses look precisely the same.
The back group shows three bright reflections; an enormous top surface reflection, a medium sized strong one which goes to one side and a teeny weaker one on the opposite side.
The front group show four bright reflections; three blue tinted and one (I presume the front surface) is rose coloured. Make of that what you will.
Re: 508mm f/7 ILEX lenses
Bill, it sounds like a tessar type.
Re: 508mm f/7 ILEX lenses
That was my conclusion too; the small third reflection was so small I did not see it the first two times I looked.
Re: 508mm f/7 ILEX lenses
Y'know, when I was writing the article I did my homework as thoroughly as I could.
2 Attachment(s)
Re: 508mm f/7 ILEX lenses
I have a couple copies of the spec sheets for the Acutar lenses, however the specs for the 500mm 6.3 is not directly shown. Attachment 200784Attachment 200785
Re: 508mm f/7 ILEX lenses
Quote:
Originally Posted by
Dan Fromm
Y'know, when I was writing the article I did my homework as thoroughly as I could.
Credit where credit is due.