Been lurking for awhile and absorbing lots from the Adapted Lens forum and Sample archive (It's already lead to me buying a Konica 40mm and the Fotasy 25mm at least) , but I thought I should chip in with some of the odd lenses that aren't represented here. At one point I decided to see how old a lens I could get, and as I'm a bit cheap about this whole affair so the pre-WW2 Leica lenses are right out. After my first C-mount lens (a pentax 6mm circular photo that I'll start a thread for later), I saw a bunch of old c-mound lenses on ebay. After looking at some here and there, I decided to do a bit of research and figure out what the oldest c-mount lens that exists could be. From the various websites that I saw, the generally referred to lens on the earliest bolex cameras was a Taylor-Hobson Cooke Cinema Lens 1" (gotta love lenses so old they were measured in standard units) F/3.5. I don't know if this particular example is among the oldest varieties of this lens, but it's certainly in the right ballpark. Lenses like this one were quite possibly made before the earliest Leicas somewhere around 1929. Anyhow, my research is a little iffy, but the intent got me about to where I'd like. The lens is quite interesting in a number of ways. For one, it's really tiny - I would never have guessed it was so small. Take the lens hood off and it's less than an inch thick. It has no focus ring - either it was set to a panfocus-infinity on the old bolex cameras screwed in the whole way, or it was simply unscrewed to focus. I've taken the second tack with this lens: It actually focuses beyond infinity when screwed tight. Infinity is about a quarter turn before hand-tight, and you can get about 4 more full turns out of it before it falls out of the mount (though I avoid going more than three to be safe). Needless to say, focusing is difficult. F-stops go between 3.5 and 16, though my experience with c-mounts that the effective F-stop after vignetting is lower than that. And speaking of artifacts, this has low contrast, flair issues (despite the tiny 1/2" thread mount lens hood), and substantial vignetting. I love it. In addition, it functions pretty well as a macro lens with a few extension tubes. Anyhow, I need to take some better pictures with it of people that wouldn't mind me posting to this forum (the pictures taken of me with this aren't good because no one else wants to wrestle with bizarro lens. Also, I'm ugly as original sin.) so for now we get pics of stuff, one at infinity and one relatively close showing the classic c-mount swirl. [There was a picture here, but it wasn't from the lens] P2052941 Last aside: I love that I have a few lenses (Pentax 110 system) that have no aperture, and this one with aperture but no focus. Balance in all things.