For many years my field camera was an old Bausch Pressman model D and I had several sets of folding bed stops for different focal length lenses. Truth is that a Schneider Symmar-S 135mm f5.6 was on it 99% of the time and coupled to the rangefinder. The only other lens I used was a 100mm f6.3 Ektar and that was just a few times. I now have a Toyo 4X5 and a Chamonix 4X5 with several lenses. I would look very close at Doremus Scudders advice above since he talks from personal experience. Of the lenses he mentions I have the 210mm G-Claron, 203mm Ektar, Fuji 180mm A and the Fuji 210mm L. My "go everywhere" 4X5 Chamonix setup is 100mm f6.3 Wide-Field Ektar, 135mm Symmar-S and 203mm Ektar. Occasionally the 180mm A Fujinon goes along. I've had no problems focusing with the smallish apertures on the 203mm f7.7 and the 100mm f6.3 WF Ektar, but things start going a little dim with the Fujinon 180mm f9 A lens. This makes for a very compact outfit and I have zero complaints about any of the lenses performances. Oh, I have more than several other top notch lenses, but they are not made for "field" cameras and are far too big and heavy for that. I like the 203mm f7.7 lens so much that I just got another one in mint shape, but in a Synchro-Compur shutter instead of the Kodak Supermatic. Now I have a spare 203mm Ektar and it's mounted on the Toyo.