I have a Horseman 980 6x9 technical camera with 90mm lens. Most of the work I use it for is landscape or architecture, and so I would like a wider lens for it.
Trouble is, many wide-angle lenses are physically too large to fit in the relatively small body. The 980 takes an 80mm lens board and the board I have accommodates a #1 shutter. I'm not sure if you could go a size bigger or not. The bellows, where they attach behind the lens board are reasonable slender so a lens with a large prodruding rear element probably wouldn't fit either.

Horseman did make wider lenses for this series of cameras (a 65mm f/7 and a 75mm f/5.6) but they are sufficiently rare that I have not seen one on everyone's favourite auction site after a year of searching.

So can anyone recommend a wide angle lens for the 6x9 format (75mm or less) that fits in a tiny shutter in a tiny lens board?

Thanks!
Jonathan