I have a Calumet monorail 4×5 with a recessed lensboard that I finally took out for some shots. It has a 65mm lens, which is equivalent to 21mm, in 35mm. The lens is so recessed, you have to use a cable release that’s hooked to a right-angle mechanism, which pushes on the shutter. Because its recessed, infinity focus is when 2 rail elements are as close together as possible, as if you’re packing it away.
The lens really needs a CLA. Only 2 shutter speeds work, 100 and 250. But I was able to just use those. The next-to-widest lens I have is an 80mm, but I wanted to go as wide as possible here.
It was pretty fun using it, but because of the marginally functioning lens, it’s only good for outdoors in full sunlight. I really ought to get the lens fixed, or get another.
I developed these at home in Diafine and a tank that you can load, then bring into the light. (As opposed to the “dip and dunk” method, where you clip the film to metal frames and dip them in small tubs of developer in the dark.)