OK... This thread got me all hopped up and I made a lens board for one of the old Petzval projection lenses I got recently. I'll be trying it on a Speed Graphic if I can get enough bellows- or go back to the drawing board and make another lens board for a Cambo...
Two questions, though. Since these things were projection lenses for Magic Lantern slides, mine don't seem to have much info on them about who made them or what their focal length might be. I've read the threads on measuring focal length but I wondered if there was a standard size for home projectors as there is a "standard" lens for any one format film.
Question two has to do with the much larger of the two lenses. I believe this one was a projection lens from a college lecture hall at the big "H" here in Cambridge, MA back at the turn of the last century. The thing is over 5" across at the flange and about 8" long. It was made in France and imported by a Boston dealer in Magic Lanterns who flourished about that time. What confuses me is that there is a notation, quite clear, on the bottom of the flange 10' 2" I'll go ahead and risk making a huge fool of myself by stating that I don't have any meaning for that other than 10 feet and 2 inches (10 degrees, 2 minutes?) Does this mean anything that makes sense to anyone?
I'll get to the fabrication room sometime soon and put that one on a camera, but for right now it's projects 1 through 456 first....
Maybe if I give up sleeping...