Thank you. I have the 5x7 back, etc. Jim sold it as a working 5x7 and as a Cirkut fixer-upper (major). The shutter works smoothly. I haven't tested the speeds yet, but they seem appropriate. The camera needs a lot of work, and I have other 5x7's so I haven't used it yet. I don't know anything about the Centar either. I will check the focal lengths and try some test 5x7's to see what the single element is like. I have a few TR triples around (can't remember what combinations -I know that is a bit pathetic). I will have to give some thought to the turntable. It would help to see one. I will be at George Eastman House in May, and will do some further research. In the mean time, if you know of any useful links it would be much appreciated. I got this outfit last August and am just starting to learn about Cirkut cameras, so pardon my ignorance and requests for basic information.