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  Friday  October 14  2005    12: 39 AM

pinholes at last!!!


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It's been a frustrating couple of years trying to make a pinhole camera out of my 6x9cm Mamiya Super 23. It started on Pearl Harbor Day in 2003

That's the Mark I version. I took it on my trip to New York City (I need to finish that site) for it's shakedown cruise. I made it out of cardboard, installed in a mounting ring from a bad lens, and it started to disentegrate before the trip was over. And then, when I got the negatives developed I discovered a terrible flare problem so, in September of last year, I made the Mark II version.

The Mark II was a much more robust installation. Unfortunately, the flare problem, while not as bad, was still there. I played around with it and found that a lens hood solved the problem but making a lens hood that didn't interfere with the shutter was getting very cumbersome. So the project sat on a shelf. It was frustrating because the quality of the images was what I wanted, sans the flare. Then a mention on an APUG form, by an f295 member, mentioned using old medium and large format shutters to mount the pinhole. Eureka! I had a large format Alphax shutter with a lens that was pretty weird that would be perfect and the Mark III version was born.

First I covered the body and back with gaffer's tape to stealthify it.

The shutter is in its mounting ring which is attached to the old Mamiya mounting ring by a few dabs of bondo.

I mounted the pinhole behind the shutter leaves. It made it more wide angle than the Mark I and Mark II and put it pretty close to the optimum position for the .0126" dia pinhole. And the shutter made a good lens hood. The pinhole is getting a little beat up mounting and unmounting it but still seems to work.

I used a piece of hardboard epoxied to the rear of the shutter with more gaffer's tape to seal everything. The press type shutter with a T setting is great to use. The slow speeds don't work. They could be useful but I can work around that with slow film. The field of view seems to be close to the 65mm lens (28mm equivalent) I have for this camera. I've got some shots on the next roll with the 65mm lens to compare. The first picture of this post is a Mark III picture. No flare. I love it. At last!

And the Super 23 has a bellows back so I will let me use different focal lengths. Might be interesting. Might not.

Update 10-2-5: Here is the information on the pinhole. I purchased it at Pinhole Resource. It's a .318mm/.0126" dia pinhole drilled in a 1.5 in. square sheet of .001" grade 400 full hard stainless steel. The focal length is 2.5"/63.5mm. I use f/190 on 6x9cm film