This past year I've picked up the Contax G 90mm and 45mm, and really like the impact I see in my photos. I do realize equipment does not a photo make, but I am interested in possibly spending (a little) more to get similar improvements in other focal lengths. Not going to go all out with $1000+ lenses - could not afford it honestly - but there is a lot of legacy glass I might be able to afford like the Contax G glass (esp if I sell the replaced glass). Based on my recent Contax G experiences, I was thinking additional Zeiss glass would be a good choice. But there are a lot of brands/mounts people refer to as "Zeiss glass". I am under the impression if it actually has the Zeiss name, they did the lens optics, with the partner building and selling the lens. I would think the lens design, as well as the quality of glass and coatings used, would largely determine the image quality. Then there are lenses using a "Zeiss design", e.g. the Russian lenses. I am also not clear on Voigtlander; I know they were part of Zeiss at one time, so do they also use Zeiss designs? So, obviously, I am a bit confused. I guess the main question is that if it is Zeiss glass or a Zeiss design, is it going to have a similar rendering (for lack of a better word)?