Originally Posted by kennylovrin
Just to kind of finish of this thread, I've decided to go for either a C Biogon or a Biogon instead. So I'll swap the 28mm for a 35mm first, then get a 28 Zeiss later. In the midst of all this I've realized I'm more of a 50mm FOV guy, so I'll go back to 35mm at the same time here - I had the 35mm nokton before but I didn't like that one either (which is why i switched to the ultron).
Not that it may interetst anyone, but I felt I needed to "close" the thread as I started it.
if it matters to you, 'tests' have shown the f2.8 c biogon to be generally a little sharper than the f2.0 variant for zeiss wide open (its tough to see the difference, as the f2.0 is an awesome lens in its own right too). However, the extra stop in f2 can make the difference in a usable shot night.
I use the c biogon myself, and I am extremely satisfied with the lens, for day shooting only. At night, I hardly need bother. I suppose the only alternatives is to either get the f1.2/f1.4 noktons (affordable, but I just can't bring myself to give up the biogon), or the f1.4 summilux (which is the ideal lens to go for, but hardly affordable to me).