Komuranon lens

[BJC0000]

Several years ago I bought (on a whim) a lens marked “KOMURANON f=500 1:7”

It came mounted in a Copal #3 shutter obviously matched to the lens as the widest marked aperture is f7

It also came with an extension marked :

“TELEMORE95 – 4x5 FORMAT for KOMURANON 500mm 1:7” on the lensless bit (RH side in picture 1) and

“TELEMORE95 – 4x5 FORMAT for KOMURANON 400mm 1:8” on the lens containing bit.

This is threaded both ends, the larger (LH) end having a retaining ring. The print referring to the 400mm 1:8 is covered when both pieces are screwed together (2nd photo)

I’ve not really used this lens except to test it, but having a recent tidy up I took another look at it. The lens in the shutter is no problem.

But for the life of me I can’t work out how the lens / shutter and the extension are supposed to fit together. The extension doesn’t have the same diameter at either end to fit either the shutter or the separated parts of the lens (and is externally threaded).

Is anyone familiar with this lens and can comment?

Incidentally, although the extension is marked “for 4x5”, the basic lens appears to cover 8x10.

 

[xkaes]

This has been discussed before -- without much resolution.

Komura/Komuranon 500mm f7

I am in the market for a 500-600mm tele for 4x5. Im considering the Komura/Komuranon 500mm f7 lens. Its faster than most other makes in this lens type and should be easier to compose and focus. Big and heavy though. I have seen 3 different versions of this lens meaning they actually appear to...

www.largeformatphotography.info

 

[BJC0000]

This has been discussed before -- without much resolution.

Komura/Komuranon 500mm f7

I am in the market for a 500-600mm tele for 4x5. Im considering the Komura/Komuranon 500mm f7 lens. Its faster than most other makes in this lens type and should be easier to compose and focus. Big and heavy though. I have seen 3 different versions of this lens meaning they actually appear to...

www.largeformatphotography.info

Thanks. I did see that thread before posting but it doesn't really address the question - what is the extension and how does it fit with the basic lens?
It must be associated with the lens because of the writing on it.

 

[abruzzi]

I don't have any specific information, but Komura seems to use the name TELEMORE95 to indicate a 2x focal extender. I've seen them for 35mm cameras, and in those cases, they all attach between the lens and the film plane. If that was the case here I'd think the threads on the flared end of the adapter (the one that says 500mm on it) would screw into the rear of the rear element, but I assume there is no matching thread on the rear element?

 

[BJC0000]

I don't have any specific information, but Komura seems to use the name TELEMORE95 to indicate a 2x focal extender. I've seen them for 35mm cameras, and in those cases, they all attach between the lens and the film plane. If that was the case here I'd think the threads on the flared end of the adapter (the one that says 500mm on it) would screw into the rear of the rear element, but I assume there is no matching thread on the rear element?

Actually, there is.
I had assumed it was a kind of 2x tele but all those I had seen before for 35mm fitted between the front element and the shutter. I have one for my Canon DSLR.
I noticed that the extension fitted to the rear element but it looked so unlikely I discounted it.
Thanks a lot, I'm sure you have answered the question!
I'm not sure I have a camera with a 1000mm bellows draw but I'll see what I can do. Thanks again.

 

[abruzzi]

that looks really awkward inside the bellows! My guess is the piece with the glass goes directly into the rearof the 400, and the other piece spaces it properly for the 500 (which may be why when it is on the 400mm text is obscured.) Since its a supposedly a 2x and the main lens is a tele, it shouldn't require an entire 1000mm, but who knows? Put it on and see if you can get to infinity, I'd love to hear if it works--1000mm on a 4x5! Also remember that 2x adapters usually lose 2 stops of speed (I think)

 

[xkaes]

That idea had crossed my mind. There were other 2X tele-converters for large format lenses. I think they were the same just sold under different names -- which I don't recall. Calumet & Horseman come to mind. They attached to the rear of 150mm lenses at created a 300mm. They weren't cheap, but cheaper than a typical 300mm lens anyway.

 

[Dan Fromm]

That idea had crossed my mind. There were other 2X tele-converters for large format lenses. I think they were the same just sold under different names -- which I don't recall. Calumet & Horseman come to mind. They attached to the rear of 150mm lenses at created a 300mm. They weren't cheap, but cheaper than a typical 300mm lens anyway.

Joe, I wrote up the Horseman 2x 150-300 TC, the story is at http://www.galerie-photo.com/horseman-2xlf-teleconverter.html. Short version, the TC's front section replaces the prime lens' shutter's retaining ring. To fit the TC to the prime lens, unscrew the shutter's retaining ring, remove the lens' rear cell from the shutter. Use the TC's front section to reattach the shutter to the board, screw the lens' rear cell back into the shutter, screw the rest of the TC on to the front section. Many of the Horseman TC's I've seen on offer don't have the front section.

The Horseman TC was made to be used with 150 mm lenses in Compur/Copal #0 shutter whose rear cell will fit inside the TC's rear section. I've never shot with it, have played with it on other lenses in #0. It seems to work with other focal lengths whose rear cells fit in the TC's rear section. No idea of image quality.

Its hard to be sure but I don't think the OP's device goes together like the Horseman.

 

[BJC0000]

Thanks to all who replied to this.
After extensive testing (a couple of exposures onto 8x10 glossy RC) I can confirm that the set-up is as described by abruzzi above. I may look odd but it works.
Flange to 'film' distance is about 540mm so within some field cameras bellows capability and many (most?) studio monorails.
I'll post some pics when they're dry and scanned.

 

[abruzzi]

very cool. I'd have to use several standards and bellows (and a lot of rail extensions) just to focus that to infinity. its also interesting and a bit surprising that it covers 8x10. Tele lenses tend to have smaller image circles.