Upload & Sell: Off
Test charts and MTF measurements are excellent predictors of a lens' performance reproducing test charts and MTF images...and, to some extent, actual photographic images as well. However, it would be certainly be interesting(in a just-for-laughs type of way) to be able to compare the Sony 20mm vs. the Zeiss 21mm. You never quite know.
Alas, being stuck with only Nikon dslrs, I'll just have to make do with my dethroned, denigrated, poorly-performing, yesterday's news, sadly pathetic Zeiss ZF 21.