View Full Version : Dallmeyer 2C

4-Nov-2006, 11:01
I have just picked up a Dallmeyer 2C. Its serial number is 15688, which should mean it was made in 1868. It has a slit for Watehose stops. The barrel diameter is about 75 mm. There is only one lens group, probably a cemented achromat. The barrel, however, is internally threaded at both ends, and the lenses fit in either end. I wonder, is this how the lens was made, or was it an aplanat (rapid rectilinear) or any other type consisting of more lenses than there are in this one now?

Take care, and have a nice day!

Ernest Purdum
4-Nov-2006, 11:39
A Dallmeyer 2C is listed amongst their revised Petzval type portrait lenses. It covered 1/4-plate. A note says "Nos. 2C and 3C are perhaps the quickest-acting lenses extant, working full aperture at an intensity of f/2 nearly.

Unfortunately, your example is misssing one lens group.

Jason Greenberg Motamedi
4-Nov-2006, 15:33
As Ernest descibes, the C series was Dallmeyer's fastest, working at f2.2. They were never common, and were (I think) discontinued in the late 1880s.

The FL of the lens should be about 6" and is designed to cover 3 1/4" x 4 1/4" plates. I think you will find that it will actually illuminate 4x5, however will have rather blurry corners and fair amount of fall off.

You are missing the rear air-spaced group. Stopped-down the front element should work alone.