Archive for January, 2012

Neretta Micro

January 4, 2012

It’s a long story, but I’ve been clearing one half of the studio/workshop and condensing another, with the inevitable consequence that a lot of stuff has headed out to the recycle yard. Naturally, that has included excavating camera parts from various boxes, bins, and packets that have been quietly maturing in the dark. One of the items I came across was the very first pinhole ‘box’ I ever made, or at least the front half of it – the other half had already gone when I gave away the Mamiya Polaroid holder that once sat behind it.

The pinhole box was dutifully stored in a new location. A day or two later I came across a Graflex “23” roll back. This was an odd one that someone had once grafted onto a Busch 6×9 Pressman, and then abandoned. The camera had come to me last year following a ten-year exile in someone’s garden shed.

After a mere twenty-four hours, I was able to visualise the two together as partners, and after a little hacking, screwing and filling, plus a few extra additions from the parts bin and the wood store, a new 6×9 was sitting on the tripod. (Well, since I already have an RB67 roll film holder it can be a 6×7, too.)

For a pinhole camera, that was already labour enough. But I also wanted to find a meniscus lens that could work with the new focal length – about 55mm. This is a wooden box with a fixed focal distance and I didn’t have a suitable helical, but the Pressman back was a Graflok and a view screen would be a straightforward way to check the focus of different lenses.

A couple of years ago a friend who made ground glass pieces for large format cameras sent me a couple of samples and I still had one that was just a fraction larger than 6×9. Cue a couple of 5mm strips of limewood, which is the right registration distance to support the glass, and a few other strips to make up a viewing frame.

Playing around with some glass I found that the rear element of an 85/4.5 Agnar was actually quite suitable for long distance if turned around. Fortunately the threads on the Isolette shutters are the same fore and aft, so I reversed the lens in its casing and put it on the front of the camera. That worked, and so well that it could be focused from infinity down to about 2.5 metres by unscrewing it to the limit, though with quite a lot of swoosh at the edges.

Another rear element that fits the thread actually gives a close focus range of around 150mm – very useful for extreme close-ups. I don’t remember where this one came from, possibly off a defunct Bessa 66 as it’s marked with a V. number (Voigtlander) on the casing, in which case it would have been a 75/3.5.

The middle element of the Agnar also has the same outer thread and the lens unit can also be unscrewed. In the past I’ve always inserted pinholes into the rear of the shutter, but this time, taking advantage of the technology on offer, the pinhole is now sitting in the second element mount and can be quickly swapped with either of the funky singlets.

Almost any camera with a normal lens mount can also be used as a pinhole just by making a pinhole body cap to replace the lens, but typically a mod cam is designed with just one style in mind. Not this one.

V. Lens

Pinhole

Agnar Rear Element (Reversed)

Agnar Rear Element (Reversed)

And doing what it was designed for.

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