The Contax IIa is mechanically a different camera, sharing no parts with the Contax II. The mount is identical, although not physically interchangeable between the two cameras.
Being a 1950s camera, the viewfinder eyepiece is still rather small, especially when compared with a Leica M, the new Carl Zeiss Zeiss Ikon or any of the Cosina Voigtlander Bessa models.
For many people, the viewfinder in the Contax IIa seems darker than the Contax II, and it has to do with the type of prism that the cameras used.
I prefer the Contax IIa, mostly because of its smaller size.
My own opinion is that if you find the viewfinder on the Contax II to be too small, you will also not be too happy with the viewfinder eyepiece on the Contax IIa.
Here's the back of a Contax IIa.
And the front of that same camera ...
Last edited by elekm; 10-10-2010 at 11:34 AM. Click to view previous post history.