M39 to M42 adapter tube

[Tony-S]

I have come into possession of a Heinz Kilfitt 600mm f/5.6 lens. It appears to require an M39 to M42 adapter (Pentax Spotmatic F) tube of the appropriate length for infinity focus. Does anyone know how I can determine the length of this tube and where I might get one?

Thanks.

 

[Bob-D659]

Maybe just a normal T-mount?

 

[Tony-S]

How would I determine this?

Thanks, T.

 

[Bob-D659]

Put the lens on a tripod, aim it at something far away like some mountain tops. Hold the camera close to the rear 42mm thread on the lens. T mounts are approx 1/4" thick internally. If you can see something in the viewfinder with that spacing, I'd guess that is all you would need.

 

[Ralph Javins]

Good morning, Tony;

There is a problem; the lens registration distance for the M-39 Leica Thread Mount is only 28.80mm, while the M-42 UTM/Pentax/Contax-S/Praktica/et cetera has a lens registration distance of 45.46mm. The M-42 Mount is much further away from the focal plane than the M-39 mount. This quickly translates to an inability to make the M-39 lens come to focus at infinity on an M-42 camera; you cannot get the M-39 lens close enough to the film plane on the M-42 camera. The M-39 mount was designed for a rangefinder camera; there is no swinging mirror to clear the back of the lens while swinging up out of the light path to the film plane.

You can use the M-39 lenses for close-up work on an M-42 camera just as they are.

OK. That is the general problem with just saying that you need an M-39 lens to M-42 camera body adapter tube.

However, the Heinz Kilfitt 5.6/600mm lens that you have I believe is intended for use with the VisoFlex housing that goes onto the front of an M-39 LTM rangefinder camera. The VisoFlex is an adapter system that has its own mirror and viewing system to allow you to focus the very long telephoto lens while using it with a rangefinder camera body. You might see if you can find the VisoFlex adapter housing that is intended for use with your lens and at least measure it. In this special and specific case with your lens, you could have a machinist make up a special M-39 LTM to M-42 UTM adapter tube with a length to match the VisoFlex housing length minus the difference between the M-42 lens registration and the M-39 lens registration. Make sure that the machinist does understand that the length specification for the face to face distance of the adapter is a Plus Zero or Nothing and Minus a reasonable tolerance; it can be a little bit shorter, but it cannot be longer. That would allow you to reach focus at infinity with the lens, and you can use the normal Asahi Pentax camera mirror system to watch what happens as you focus the telephoto lens. The back of the adapter will take the standard M-42 specification of 42mm diameter by 1.00mm thread pitch. You need to check and confirm that the Kilfitt lens does have the M-39 LTM specification of 39mm diameter with 26 tpi Whitworth pattern threads. Also, you might ask some of the older guys with the Leica cameras on the Rangefinder Forum if they can help with the measurements you need.

And, it will be a manually operated lens; no automatic operation of the lens diaphragm to stop down just before taking the photograph. You need to close the lens aperture to the taking f-stop just before you release the shutter.

This will be an interesting project.

 

[randyB]

Most telephoto Kilfitt lenses for 35mm use have the LTM thread at the back of the lens, they made adapters for different brands of cameras, Nikon, Canon FD, Leica SM and Reflex, Exakta plus many others. You can find the adapters on the auction site but expect to pay thur the nose for them. These are manual lenses, no automation at all. Kilfitt lenses were very high quality at the time of their manufacture, but have been surpassed by modern ones. Your lens is well worth paying for the mount adapter.

 

[gorbas]

Hi, some 25 years ago I tried 300mm Kilfitt lens originally with Arri standard mount (for 35 or 16mm film cameras). After taking off Arri mount I used simple M39 to 42mm ring and then added as many M42 extension tubes as necessary to mount it to Nikon SLR body (I had m42 to Nikon adapter). Unfortunately I can't recall how many extension tubes I needed, maybe around 75-100mm.
Good luck!
Goran

 

[Tony-S]

OK, there's a black adapter ring in the box that the lens came with that has "LE-T Japan" written on it. Can I assume this is a Leica M39 to T-mount adapter?

 

[Tony-S]

My M42 extension tubes of total of 65mm with the lens adapters does not reach infinity - it's much closer. So I need less length, right? The tube screw into the T end of the adapter, but not very far, since the pitch is different. I didn't go any further when I felt it tightening.

Here's a photo from my SD15 (sorry it's digital, but this will be the easiest way to get it figured out).

 

[John Koehrer]

Correct, less extension.

If you take the tube out does it go to infinity?

 

[BrianL]

OT but, the Visoflex also makes the Leica capable of closeup and macro photogrpahy using the regular Leica lenses. I use mine for that purpose.

 

[randyB]

I scanned this from my Kilfitt info I saved from the 70's .

 

[Tony-S]

That's interesting, but I'm not sure how to read it. It says for Pentax I need "2617 anpa". What is an "anpa"?

 

[randyB]

"2617 anpa" is the code for the mount. The "anpa" is just the letter part of the code, probably means something to the parts/order department when they were still in business. It will look something like an extension tube. It should have "Kilfitt" and the code stamped or printed on it somewhere. These adapters are quite difficult to find and can be expensive ($100-200 just for the adapter) but they do show up from time to time.

 

[gorbas]

Tony, you should use M42 extension tubes on the end of lens M39 thread, not on the end of Kilfitt-T mount adapter. T mount is 42x0.75 mm and Pentax screw mount is 42x1 mm, so you have right thing, it will not allow you to turn more then 3/4 or one full circle. Just find right T2 adapter for you camera body! There are plenty of them and they are very affordable!