I have an unusual small Petzval lens--a Baush and Lomb 6" Rectinar lens with aperture control. I don't remember seeing any other small Petzvals with apertures, so if you want one--this is your chance. The glass is in very good condition and the rack and pinion, and aperture operate smoothly. It looks to be about f/6 and would fit nicely into a spare shutter or mounted directly to a lens board. This was likely a projection lens and the (unmarked) aperture was used to shutter the lens, but it can easily be used to stop down the lens. This lens would be perfect on a 4x5 if you like some swirly bokeh.