Making a K-mount folder

Ian Grant · Feb 4, 2008

Being slightly crazy I've just bought a third 9x12 camera for 2.50 euros, it has no lens, but appears looks sound apart from that.

Now Voightlander made 9x12 AVUS cameras with changeable lenses and I've seen an Ihagee Exacta bayonet version too so I'm considering fitting a K-mount to the camera - I have a body mounting ring off a scrap Pentax, and I'm figuring on using K-mount body caps to mount the lenses on.

My thinking is a very small, light & flexible LF camera, use-able with 9x12 film or a roll film back for 6x9.

Ian

Ole · Feb 4, 2008

It was the Bergheil, not the AVUS. Apart from that, it should work.

BradS · Feb 4, 2008

but....what K-Mount lens has enough coverage for 9X12?

DBP · Feb 4, 2008

I presume you are talking about using the mount, not the actual lenses, as the flange to film distance is pretty short for K-mount. I would probably go with a simpler mount, like the Exakta, or maybe the T-mount, M42, or M39.

Ian Grant · Feb 4, 2008

Well I got the idea from seeing a 9x12 with an Exacta mount on ebay, whether original or fitted later difficult to say but as Ihagee made MF cameras quite possibly original. But the M39, M42, Exacta and Tmount are all quite narrow compared to the K-mount. So as I already have a K-mount lens mount off a scrap Pentax that's a good staring place, an EOS mount would be even better

Quite a number of my LF lenses could easily fit on a Pentax body cap, just by drilling the rights size hole for the shutter, so I could fit a modern 150mm Sironar, and 105mm Trinar (6x9 only) plus a 90mm Angulon, I just tried and the Sironar rear elements fit through a K-mount, the other suggested mounts would be too limiting.

So the idea is looking very promising, remarkably easy and cheap, if it works I'll post some images.

Ian

BradS · Feb 4, 2008

But, I still don't understand how it would be better / cheaper than say, a copal #1 flange? You know, like the flanges that are atteched to older, thick wooden lens boards. The flange is attached to and stays with the lens board....then, anything in a copal #1 is instantly mountable on that board....Would this not have a similar result?

Ole · Feb 4, 2008

Since I own not only two Bergheils (9x12 and 6.5x9) but also additional mounting bayonets, I can easily understand the attraction of a quick bayonet lens mount.

One interesting "cross candidate" is mounting the lens bit off a Leitz Hektor 135mm in a 39mm to 42mm to PK adapter - it covers 9x12cm with movements.

Ian Grant · Feb 4, 2008

Brad, good point except these 9x12 cameras don't have much space on the front, my lenses are in a variety of shutters, 00, 0, older Compur's etc, and K mount adaptors are cheap from China if I decided on using metal instead of plastic body caps.

As Ole knows these 9x12 cameras were once extremely common in Europe, and the film size is just a touch under 5x4 (modern 9x12 film holders are larger to fit the International 5x4/9x12 backs) but these cameras are very mush smaller than 5x4 models. Many of these cameras are extremely similar, and a number of manufacturers used common parts, the major differences being the quality of the lens & shutter. Kodak were so impressed with these cameras they bought Nagel, putting Rochester sourced lenses on them and for their top models added a Kalart Rangefinder.

I bought this one for parts, and will remove the bright-finder sight to use on another 9x12 camera I own, this one's tatty so I may jazz it up a little - repaint it, fit the K mount and give it to my wife

Cameras should be fun to use . . . . . .

Ian

Dan Fromm · Feb 4, 2008

Ian, I think you're showing us the corrupting power of found money. Or, in your case, found camera. You have the thing and can't resist the temptation to make it useful ...

BradS · Feb 4, 2008

Ian Grant said:
Brad, good point except these 9x12 cameras don't have much space on the front, my lenses are in a variety of shutters, 00, 0, older Compur's etc, and K mount adaptors are cheap from China if I decided on using metal instead of plastic body caps.

Cameras should be fun to use . . . . . .

Ian

Ah, yes....excellent points, both.

Cheers!

Ian Grant · Feb 4, 2008

You asked an interesting question earlier:

BradS said:
but....what K-Mount lens has enough coverage for 9X12?

I think these cameras collapse close enough for folding to allow 35mm lenses to be be focused & used, it will be interesting to try a few K mount lenses, particularly my 17mm.

As Ole says

Ole said:
One interesting "cross candidate" is mounting the lens bit off a Leitz Hektor 135mm in a 39mm to 42mm to PK adapter - it covers 9x12cm with movements.

Unless you try you don't know

Ian

Ole · Feb 4, 2008

Ian, I've been using a Hektor like that on a Pentax Mz-5n, with macro bellows for focusing.

And since I had it off the barrel extension and focusing mount anyway, I stuck it on my Speed Graphic for a look. I believe it was originally designed as a LF lens!

Ian Grant · Feb 4, 2008

Well, strange you say that, occasionally Leitz lenses appear on ebay with LF coverage. Leitz sat on Barnacks Leica for quite a time before it went into production. Historians are only interested in Leica as a 35mm manufacturer.

Ian

paul ewins · Feb 4, 2008

Something like this then.....

Basically, a piece of aluminium with a copal 0 size hole is screwed to an old lens mount. The lens is then attached in the normal way. I've got a 150 G Claron, 105 Leitmeyer and 90 Angulon mounted this way.

The body mount is best done by using a short extension tube as this gives you the little lever and pin to hold the lens in place.

Ian Grant · Feb 5, 2008

paul ewins said:
Something like this then.....

Exactly like that

Ian

jd callow · Mar 7, 2008

very cool!

Dan Fromm · Mar 7, 2008

paul ewins said:
Something like this then.....

Basically, a piece of aluminium with a copal 0 size hole is screwed to an old lens mount. The lens is then attached in the normal way. I've got a 150 G Claron, 105 Leitmeyer and 90 Angulon mounted this way.

The body mount is best done by using a short extension tube as this gives you the little lever and pin to hold the lens in place.

Fine, wonderful, but your folder has a fixed back. This raises two questions.

I can see you to set the thing up to focus one lens. What will you do with another lens with a different focal length? Focusing on a ground glass doesn't seem possible.

And what will you do with a lens whose rear cell's outer diameter exceeds the K-mount's inner diameter? Again, unless you set up to shoot a whole roll of film with the lens, the old unscrew the rear cell and reattach after the shutter/front cell is mounted trick won't work.

Ian Grant · Mar 7, 2008

Dan, all my modern LF lenses for my 5x4 and 9x12 will fit the rear cells through a Pentax K-mount, even my Rodenstock 90mm f6.8 Grandagon. Also all my German vintage lenses in Compur shutters, the only lenses I have that think won't fit are Illex Paragons.

Ian

DannL · Mar 7, 2008

You've got an excellent project going here. What's the current status? I have a spare 9x12 Avus in storage with fogged elements. Maybe I could put a Kiev 60 mount on it and pop a Mir-26 on the front. That should make for an interesting peice of gear. (but will it float?)

Ian Grant · Mar 7, 2008

The project has to wait 3 more weeks the cameras and bits are in the UK, while I'm by the Aegean

Ian

bhorn · Nov 1, 2008

Did you ever complete this? How did mounting the lenses on K body caps work out? were they rigid enough? How did you go about cutting the holes. I currently do not want to spend the money for a drill press but have a variable speed drill, a dremel and various tools made for cutting paper/cardboard. Any suggestions?

Thanks,

Bruce

Ian Grant · Nov 4, 2008

Yes I made a first prototype about3 months ag while in the UK, I just used a metal hole cutter and a semi-circular file & fitted a couple of Copal 0 lenses/shutters to a K mount body cap. I used a 150mm Sironar & 90mm Angulon. I should have taken some photo's but it's no different to Paul Lewins in practicality, but the lenses are back in Turkey now.

Ian

df cardwell · Nov 4, 2008

Ian

Good idea. My Juwel would be a good candidate for this. Let us know how it works.

don

bhorn · Nov 4, 2008

Did you end up using metal body caps or plastic? I am thinking of trying out the plastic ones first to see if they are rigid enough. Although people posting in other threads cautioned about the dangers of using adjustable drill bits freehand, I am thinking that if I use my cordless drill at a very low speed and clamp the cap to a big piece of wood it should be safe enough just drilling through plastic. Does that seem reasonable?

I also have a strong iris and am thinking of mounting that to a K mount with a home made lens board in between. I may use an extension tube for the k mount on that one as the strong iris is huge (I think it should hold at least a #3 shutter) and that and the board together will be a bit heavy.

Does anyone know what the smallest strong irises are that were ever made? Most of my lenses are #0 or #1 at most and it would be nice to use a smaller one if I could find it. Also, any places to find them other than eBay? That is where I found this one but they don't seem to come up all that often.

Thanks,

Bruce Horn

Ian Grant · Nov 4, 2008

Plastic, if I could find metal that would be far better.

The shutter size is dependent on the speed of the lens and the size of the elements closest to the iris/shutter.

Ian

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