[citro1]

Thanks for your reply!
 
Here are some reviews, same sources, verdicts for the Nikkor being along the lines of 'impressive', for the Sigma more like 'not bad'.
First two using APS-C, the MFT charts look better for the Nikkor in each case, peaking at f/5.6.
 
http://slrlensreview.com/web/reviews/nik...ens-review
http://slrlensreview.com/web/reviews/sig...ens-review
 
http://www.opticallimits.com/nikon--nikk...est-report
http://www.opticallimits.com/canon-eos/2...ew?start=1
 
http://www.kenrockwell.com/nikon/28f28ais.htm
http://www.kenrockwell.com/sigma/30mm-f14.htm
 
 
To put things in perspective, I'm generally trying to get a better understanding of lenses, criteria of quality, and how opinions on the web come about.
 
Not unhappy with the Nikkor :-) images look good of course and it has unique aspects like the minimum focussing distance.
 
I was just surprised because I expected superior image quality, based on available information.