Galvin 2x3 Adapter to use Wista/Technika Lensboards
The Wista/Technika lens board design is probably the most widely used small board on large format cameras, either directly or via an adapter board. While Linhof (Technika) the originators were consistent, and most clone type (Wista, Shen Hao, Nikon, etc), are close, a lot of home made variants are not quite standard. Any adapter needs to try and accomodate common variations without sacrificing function.
The Galvin 23 Board
The Galvin 2x3 camera uses a square board 150mm square. This fronts a standard with a 90mm square aperture. The Wista/Technika board is a little larger, but the circular light trap rim on the back will fit in the standard aperture, so it is likely that most lens rear elements will fit through.
The Galvin has a mounting method that uses two small domed screw heads in the lower corners, and rotating spring clamps for the upper two corners. Any adapter has to accept these connections. Provided the adapter holds the guest board securely, there is no reason the Galvin adapter cannot be used in any of the four orientations. This means that a lens on a guest board with a built in offset can be mounted with extra rise/fall or shift. The lens controls may not be ideally located doing this, but the extra movement may be useful.
The adapter consists of a Galvin board with a receiving frame for the guest board built on top. Allowance has to be made at the corners for the Galvin locking latches. The usual retainer for this type of guest board consists of a fixed strip at the bottom, and a sliding latch set at a slight angle to the face of the board, so that it tightens down as it slides into place.
The only complexity in the design was getting the right angle for the slope of the locking slide, and adjusting the angle of the holes for the heat-set sockets so that they were perpendicular to the slope, and not the adapter surface.
The design works with printed latch parts, but metal (steel or brass) might be a better substitute.
The device works for all the boards tested, though some take the latch better than others. It is certainly convenient to have most of my 4x5 lens set available. The Galvin board is sightly quicker to mount, but none of my other cameras use the Galvin board.
This project used Hatchbox PLA in black, and was printed at 0.2mm layer height using a o.4mm nozzle. The design was done using OpenSCAD.
The only additional parts were four heat-set sockets and the matching screws used to secure the clamps holding the guest lens board. These need to match the thickness of the board.
Some plastic-safe matte or flat black paint is useful for reducing reflections. The parts should be thick enough to avoid light leaks, but paint is a cheap precaution.