I've got a Jamin Darlot that misses the corners of 11x14 at infinity, but fully illuminates at portrait distances. Not sure what the f-stop is, in part because I haven't been able to calculate the actual focal length- no waterhouse slot, so I can't tell quite what the nodal point is to measure from the ground glass. It appears to be something around a 14" or so, and I'll put it somewhere between f5 and f8. The barrel itself is somewhere around 10" long, and 4 1/2" in diameter. I've got it ghetto-rigged on a 6 1/2" sq. lensboard. With the lens being wide-open all the time, the depth of field is quite minimal. It should produce very nice swirly-whirlies in the background.