Modifying a Sinar to Wista Lensboard Adapter for an Intrepid 8x10

Modifying a Sinar to Wista Lensboard Adapter for an Intrepid 8x10

April 2018: Intrepid have announced their own reducing lens board, but I will leave this page up in case anyone else is interested in modifying a rear-projecting Sinar to Wista board.

Most of my lenses are mounted on Linhof/Wista size boards. This includes one that I plan to use on my 8x10. Rather than remount a lens onto a bigger board to use the 8x10 I planned to use an adapter for the bigger front standard, and leave the lens on the smaller board.

The Problem

There are two general types of lenboard adapters to mount Linhof/Wista style boards onto a Sinar mount. One type consists of the Sinar board with a circular aperture, and the usual Linhof/Wista style clamps placed above and below. This style has no rear projection on the Sinar board, but does away with the usual recess that the smaller board uses.

The other type has a recess in the Sinar board, with a circular aperture behind it, and the mounting clamps above and below. There is an extra extension (<2mm) on the back of the Sinar board to accomodate the depth of the recess. Normally this is not going to be a problem - Sinar cameras have wide, square front standards.

The Intrepid 8x10 has a front standard that takes a Sinar size board, but looks a little like a scaled-up Linhof/Wista front standard, with a large circular aperture. The extension part of my adapter board overlaps the circular cut-out, so it is too thick to mount. This left me with three options - get a different board, modify the camera, or modify the board. I chose to modify the board.

The Modification

A trip to the hardware store scored some 1/16" (~1.5mm) and 1/8" (~3mm) birch ply. The thinner plywood was used to make a frame the size of the Sinar board, with an aperture just large enough to fit over the extension on the back of the Sinar board.

Cutouts were made top and bottom to accomodate the Sinar style clamps on the camera. The thicker plywood was cut to the size of the Sinar board, and a center hole of 3 1/2", roughly the size of a Linhof/Wista lens throat, was drilled out.

Four holes were drilled in the corners of the Sinar board to take domed wood screws.

The plywood was assembled with a touch of glue, and the wood and metal adapter board were clamped together, and the screws inserted. The screws were a touch over-long, so the points were cut off using a rotary tool.

Finally the wood was painted flat black, and some black fabric applied to the rear edges to tighten up the mounting. The plywood was a little thinner than the Sinar standard, but the fabric (cut from an old lens wrap) did the trick.

In Use

The modified adapter mounts onto the Intrepid with the board clamps gripping the thicker plywood part, and fitting into the recesses in the thinner plywood insert.

The original metal adapter board happily sits on the front of that, and is semi-permanent. If I have a need to mount a Sinar board the adapter can be removed, but mostly it will stay on the camera.