ChrisC
Established
..... Where is fails is in low light where it's vignetting at 2.8 becomes a big problem. It's also not coded, which gives the Summarit the advantage.........
Don't all Zeiss C-Biogon 35mm lenses have the grooved flange for easy-[ish] coding? So why not code it and have some vignetting correction applied. Or alternatively; strip out the Summarit's coding and see how it vignettes without correction. Either option would give a fairer playing field from which to consider each lens' comparative vignetting performance. Surely better than an apples/oranges comparison.
Or have I misinterpreted your sentence; and that you coded your C-Biogon, but meant that the disadvantage to the Zeiss was in it not being factory coded?
.............. Chris