Bausch & Lomb 20" Process Lens (copier lens?) HUGE coverage! Here's a magnificent looking beast of a lens from Bausch & Lomb. I suspect that it's a process lens or maybe a copier lens. There are threaded rings for mounting. . Excellent condition: the lens elements are clean and free of scratches. I see no fungus or separation - just some slight dust and a very light haze - a cleaning is recommended for best results. The aperture is clean and working but offers a limited range f/8 to f/16. The aperture operates smoothly. Sorry, no sample photos taken with these lenses.