STEREO MEDIUM FORMAT CAMERA

USING MAMIYA C330 LENSES

This project started as a wooden hand made camera. Obviously it didn't end up there!

A short update on the wooden version that used to be on this web page: The wooden camera body was constructed of laminated 1/4" thick mahogany cut on a CNC mill. It resembled a butcher block in construction but had many complicated internal shapes. Actually the camera body was going along very well until I tried to hang the lenses onto it. I fought with that for months, and finally decided that it was the lenses that I really wanted to try out, not the camera body. So I put the camera body aside and found a quicker way to test the lenses out on a stereo camera.

I decided to use the Sputnik camera body as a starting point. It is thick plastic, sturdy, compact, and lightweight. The general design of the camera body is OK, it's the lenses that are questionable. I bought a Sputnik parts camera from e-bay for cheap and removed the lenses. Now I was cooking! All I had to do is attach the Mamiya lenses and off I go………..

I also decided to use a standard 35mm macro focus rail system as the source for the bellows and rack.

The first thing I had to determine was where the lenses had to be located to focus at infinity. (Note: remember that Mamiya 80mm f/2.8 Black TLR lenses have to be rack focused, not using a rotating front element like the Sputnik). I located that point then found that I had to machine off some plastic from the camera front face to allow the lenses to be set in further. I made an aluminum face plate to mount the lenses. Then I tried it out.

The lenses weren't close enough to focus at infinity. Off comes more Bakelite from the camera front. Still not focused! More Bakelite…..no focus…..more Bakelite…….focus! Let me tell you, I removed absolutely the maximum amount of Bakelite, all the way to paper thin. But it was enough.

The next step was to make the twin bellows. The 35mm macro rail bellows was cut in half and shortened to make the two bellows. The 35mm bellows are the perfect size for a single Mamiya lens. I glued a thin aluminum attachment flange to each end of the bellows.

 

The lens plate now needed to be attached to the camera. Looking at the left over 35mm macro rail parts made it all come together. The focus rail is perfect for a sturdy, smooth focus attachment. A little modification to the rail length and other things and I was on my way.

I machined an aluminum clamping block to attach to the camera tripod screw. The focus rail was clamped inside of this block.

THE LOOSE ENDS TO FINISH IT UP:

Since I did not use a third lens for focus (to keep weight down) I used a rangefinder viewfinder from a Polaroid ColorPack camera. These are real high quality, inexpensive rangefinders. I put a distance scale in front of the rangefinder so I can read the distance to the object after moving the rangefinder arm. I then set this distance on the focus rail distance scale. It's a two step process, but quite accurate. I tried to link the lens plate directly to the rangefinder but the gear/lever ratio necessary to match the two together made it impossible. I tried three designs but all were over stressed and broke. I'll keep working on this problem.

The lens shutters were mechanically linked using the Sputnik linkage. After some adjustment it worked very well for synch. No other lens items are linked yet.

The inside of the camera was lined with black flock paper. Templates needed to be made and then the shapes are transferred to the flock paper. Everything fits perfectly if done this way.

The rear door light trap groove was lined with thin strips of black flock paper on the angled side only. This was done completely around the camera with no gaps. All other inside camera surfaces were painted flat black. Another black flock paper strip was added in-between the two doors where they butt together. This camera has no light leaks!

Since I only bought two lenses I couldn't match them for focal distance. The lenses were different by .6%. My test shots show that this mismatch is not a problem. I cannot detect any problem with viewing the slides.

My test shots using ISO50 Fuji film were great. I can't supply any scientific proof, but I am extremely pleased with the sharpness, contrast and lack of distortions of the Mamiya TLR lens. The stereo image is impressive.

Another thing I really like is that this camera is the lightest weight and smallest size medium format stereo camera I have ever used. That means a lot when you are lugging around cameras on vacation.

All this from the Sputnik!

 

COPYRIGHT 2001 BY ALAN LEWIS