For Lens Nerds; Today's Oddity - DPChallenge Forums

Canon EF 28-200mm f/3.5-5.6 USM

01/06/2007 01:49:12 PM · #1

Here's one that I literally inherited with a bunch of my Dad's stuff. It was made by Schneider Optics, some time prior to 1967... much prior, since my Dad had it since then, and it was removed from some piece of industrial gear. It's actually not marked as built by Schneider, all I have is my Dad's notes to that effect.
It has a 24-inch (609mm) focal length, at f/5.6. It has a diaphragm that allows it to be stopped down to f/8; it's marked to f/11, but there is a mechanical stop that limits it to f/8, and I really don't want to dissassemble it to figure out how to remove the stop.
For size comparison, the lens next to it is the Canon 50/1.4. The front element of this beast is over 100mm across. The rear element is about 75mm across, and it projects an image circle about 200mm in diameter (!!) There is an internal lens group that moves and apparently adjusts the magnification slightly. I suspect this monster was used in reproduction equipment.
I'm sure this thing will prove useful, I just haven't figured out quite how yet ;-)

BakerBug

Canon EOS-20D

01/06/2007 01:57:21 PM · #2

Kewl! :-)

Bear_Music

Samsung Galaxy S24, S24+, S24 Ultra

Sony 24-70mm f/4 Vario-Tessar T* FE OSS

01/06/2007 01:57:40 PM · #3

Yah, that's a reprographics lens I think. Hence the magnification adjustment. Aperture is limited because it's designed to be used on a flat field where DOF is not an issue, but crispness is.

R.

Nikon AF Nikkor 50mm f/1.8D

01/06/2007 02:00:30 PM · #4

Yeh Robert, the thing that tipped me off to the repro use was the 1:1 marking. Dead giveaway. It's one *massive* piece of glass & metal, weighs in at 6 pounds.

Edit: The flat field properties of the lens just might make it useful as an objective for a fast, moderate focal length telescope.

Message edited by author 2007-01-06 14:03:10.

wavelength

Nikon D300

01/06/2007 02:09:05 PM · #5

Originally posted by kirbic:

Could you just put the monster on one end of some PVC, and hook the 50mm up on the other as an eyepiece? I imagine this question reveals how limited my knowledge of optics really is.

Tamron 70-180mm F/2.8 Di III VXD

01/06/2007 02:20:59 PM · #6

Originally posted by wavelength:

Could you just put the monster on one end of some PVC, and hook the 50mm up on the other as an eyepiece? I imagine this question reveals how limited my knowledge of optics really is.

That's sorta my plan as a first test. I will use a telescope eyepiece, but the PVC tube is pretty much where I'm going with it. I'll actually need two tubes so it's focusable, but that should't be hard to rig up.

MadMan2k

Sony Alpha a6400

01/06/2007 02:35:03 PM · #7

Cool. You should build a view camera body to put it on and use a flatbed scanner for a scanning back to make digital files :p

wavelength

Nikon D300

Nikon AF Nikkor 50mm f/1.8D

01/06/2007 02:36:13 PM · #8

Originally posted by kirbic:

Originally posted by wavelength:

Could you just put the monster on one end of some PVC, and hook the 50mm up on the other as an eyepiece? I imagine this question reveals how limited my knowledge of optics really is.

That's sorta my plan as a first test. I will use a telescope eyepiece, but the PVC tube is pretty much where I'm going with it. I'll actually need two tubes so it's focusable, but that should't be hard to rig up.

I'd like to see that, I've seen some of these in a shop up in Weston, MO. Morts Camera Collection or something. He also sells litographs of old tin-type photographs of vaudeville performers that his great uncle used to take. Would be a cool project with my 7yo daughter, who wants to be an astronaut.

MelonMusketeer

Nikon D7000

Nikon MF 50mm f/1.4

01/06/2007 02:59:46 PM · #9

Redneck kids use them with sunshine for frying ants and starting brush fires.
I think Bear is right about it being a repro lens. I have seen similar things on the "ebay" site while hunting lenses.
Great idea from "madman"

Message edited by author 2007-01-06 15:01:36.

Spork99

OM System OM-1

Canon EF 100mm f/2.8 USM Macro

01/06/2007 03:18:39 PM · #10

I wanna see it on the front of your 5D!!

With an image circle that size, assuming that's where the image was focused, the biggest standard format you could cover would be 4x5" and a 24in lens on that format has about the same FOV as a 180mm lens on a 35mm camera.

It'd be interesting to make a pseudo view camera with a flatbed scanner, but the telescope is a good idea too

wavelength

Nikon D300

Nikon AF Nikkor 50mm f/1.8D

01/06/2007 03:40:17 PM · #11

Originally posted by MadMan2k:

Cool. You should build a view camera body to put it on and use a flatbed scanner for a scanning back to make digital files :p

I'm not quite sure how you would purport this to work... maybe if you disable the light on the scanner to get rid of internal refractions, but it still seems a bit far-fetched to me. The "focus" of the scanner would be hard to determine, possibly a sheet of high-grade lucite-like material to create the film or sheet to be scanned? Would also be an interesting project to try, though. A high-quality flatbed could give you a pretty sweet image size.