Quote Originally Posted by Top-Cat View Post
On the lens itself it says:

Voigtländer Anastigmat AVUS 13,5 cm. 1:6.8 D.R.P. 291916. No227131.
The serial number puts it in late 1924 or early 1925, as far as I can tell. From looking at the Vade Mecum, I'm not totally clear on what type of lens it is; "Voigtlaender Anastigmat" in the interwar period seems to refer to a triplet, but there's a one-liner that describes the "Avus" lens as "a reversed Skopar type design with 4 glasses, ie a 'rasset' type design". To complicate matters, it also says that Voigtlaender appear not to have made "a 4-glass triplet" (meaning a Tessar design) until 1927, which is too late for your camera.

So on balance I'd say the lens is likely a triplet, or just maybe an early version of the Skopar. It should work fine; you'll see some light falloff and softness in the corners of the image, especially wide open, but in the center and stopped down, a good triplet should be quite adequately sharp, and many of us like their character. Good catch!