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[Charles Barringer]

I just got a 2 1/2" optical assembly for KE-4 from the great auction site and was wondering a few things. Serial number is RM189.

Does anyone have info on the optical design of this lens? Any ideas of total production of this lens? Or of any of the elements of the system? Any good links for more info about the KE-4 / 6 systems?

Does anyone have a clue if the focusing mechanism / bayo mount for the 4" lens might fit the 2.5" or be adaptable to it? (Actually, I might as well ask if anyone has a spare focusing mount for the 2.5" they would part with, or an organ donor needing new glass.)

Could someone send either a scan from a publication or some pictures of the complete lens so I could see what I should be aiming for?

thanks
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Charlie

[Les]

Since I only handled one these cameras once and Todd Gustavson was looking over my shoulder when I did it, I can really say much about switching mounts between the 2.5 and 4" lens. I have some literature (a civilian brochure and a reprint of a review from US Camera) but they talk in generalities keeping lens formulas to themselves.

I also have an engineer's paper on the rangefinder and coupling system of the "Graphic 70" (civilian name) and while it's heavy in detail and math, I don't think that's what you are looking for either.

Production is sketchy, the military accepted 490 out of a 500 unit contract, though it seems they allotted 1000 serial numbers for the civilian model, how many were actually made is anybody's guess, though the retail price of the outfit being $1850 in 1955 probably kept production low (adjusted for inflation, that's $14K+, almost makes the MSRP of $8000 for a Nikon D3x look cheap........almost.)

Photos I can help you with. they aren't the best, but the best I can do for now. look quickly because my dear old ISP is closing this server on the 19th and the link will die. They gave me a new site, but it's flash based and I haven't figured out where to put the AG1's in to make it work yet.

I also have the military service manual but it's on microfiche and I don't have any way of scanning/copying a 1cm square and make it readable. If I have time, maybe I can to a quick scan with my old microscope and see if any lens diagrams show up.

(camera, flash, and three lenses)
http://home.twmi.rr.com/lnphoto/combat70web.jpg

close up of the wide angle lens:

http://home.twmi.rr.com/lnphoto/combat70ektarweb.jpg
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"In order to invent, you need a good imagination and a lot of junk" Thomas Edison

[Charles Barringer]

Thanks for the info and the images, Les. The shot of the 2.5 is very helpful as it gives me an idea of the proportions of the original to use as a guide in my reconstruction efforts.
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Charlie

[scifan]

The focussing mount from the 4" lens would not work on this camera.You will have to find an original mount for this lens if you want to use it on the combat graphic.This lens is the rarest of the three made for the 70mm combat graphic.I wish you luck in finding the parts to repair the lens.

[Charles Barringer]

Thanks for confirming what I had already determined about the unsuitability of the 4" focusing mount for this lens. I realize that it will require a miracle to find the missing components for this lens (or to find a complete one), but hope springs eternal. Thanks.
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Charlie

[scifan]

Total production of this lens is probably only a few hundred units.

[Charles Barringer]

That confirms what I had heard. That's also the reason I snagged this one even though incomplete, figuring that a bird in the hand ... even though the lens as such is useless for its intended function.

I intend to jury-rig it so I can test it out on my baby Speed, just to see if the short, wide Ektar is where it should be, optically.

The reflections suggest a symmetrical 4-element lens - 8 a/g surfaces 6 of which have similar curvatures and 2 much flatter. I remain interested in learning more about the optical construction if anyone can help.
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Charlie

[pinelakes09]

just purchased ks-6 still camera set in original case, seems like everything is there including ke-4 camera, lenses, flash, etc but don't really known what should be included. great case and mint condiion. what do I do next. any thoughts bob at pinelakes09@comcast.net
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have located complete ks-6(1) still camera set in original case including ke-4(1) camera

[C. Henry]

For what its worth the "RM" in the serial number translates to a 1953 date of manufacture for the lens.

C. Henry