A 6 by 17 swing lens camera for medium format film

Image of swing lens camera
6 by 17 – leather, brass, wood and Tessar

This camera marks the point where 19th century design and 20th century technology came together in my work. In attempting to design a medium format camera for my own use with vintage style drive techniques I decided that I’d rather have modern performance. So in 1991, after adding a motor, a microcontroller and some FORTH code, I ended up with 16 stops of shutter speed range using a single slit width. A compact Zeis Tessar lens in a rotational “bellows” of 0.009″ thick pigskin does the imaging chores.
Mahogany, brass, leather and a black box!

photo of sea lions on the beach
Waiting for the females . . .

This project was my first encounter with Maxon, a Swiss manufacturer of high precision motors, gearheads and controls. The camera uses a closed loop servo system consisting of the motor, a planetary gearhead and an optical encoder plus the servo controller required to run this system. A Motorola 68HC11 based micro-controller running the FORTH  programming language issues the commands necessary to interface between the user and the servo system. The micro-controller system came from New Micros, a company with an exhaustive line of micro-controller systems. At the time – 1991 – there was a tech support staffer who was among the best I’ve ever encountered. I was just learning how to use the technology and he was amazingly skilled at ascertaining what my skill and knowledge level was at various points during the project.

Inside the film compartment
Inside the film compartment

My original design goal for this camera called for building a conventional, historical drive system using a spring-based motor, gear train and a vane-type speed governor that uses the air resistance of a spinning vane to control the panning speed of the lens. Different size vanes result in different speeds. They were used on a number of cameras but I suspect the reliability was not great. I got part way through building the mechanism before deciding that what I really wanted was a camera with really good functionality. What resulted is pretty amazing with respect to the range of shutter speeds that are possible.

The potential shutter speed range extends beyond the 16 switch positions dictated by the available switches at the time. I wanted to maintain some of the Jules Verne like quality of the camera, so I opted for a very simple interface with a mechanical speed selection switch rather than some kind of button controlled menus system. The resulting black box controller has led many observers to suggest that the camera has a Steam Punk feel to it. Although a lot of Steam Punk objects are simply decorated to appear as if they could have been created in the 19th century, I was at least as concerned with obtaining a high level of functionality as I was in honoring Mr. Verne.

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