New Zeiss Touit 12mm delivers highest level of image quality on Sony Nex-7. This Zeiss lens is quite large but is a real top performer, very impressive.
On the minus side for the Touit is a strange behaviour with AF on Nex-7, it is nearly useless because slow. The lens is pumping back and forth for each focus. A firmware update is by the way expected from Sony this summer. I hope it will correct this drawback. Manual focus is now what I use, and this is very comfortable on the Nex. Another drawback is that the lens is not recognized by Nex-7 to adjust microfocus. Not a major drawback on this 12mm but definitely one on the Touit 1.8/32 which is shifted on the lens I have. This will come maybe with next firmware too.
Here are 2 pictures taken with Nex 7 (left) and Leica M 240 (right) at f4 on both lens (Leica has handicap of full aperture, noticeable on corners)