Nokton has lens CPU and hence save the hassle on setting lens data on many DSLR (for those can meter with AI-S), and made metering possible with almost all DSLR and SLR.
I do not have the Nokton, but a search turn out a few test photos:
http://www.dchome.net/viewthread.php?tid=446200&page=1
http://www.dchome.net/redirect.php?tid= ... o=lastpost
While some of them do look rich in colour, but not on the little baby face.
I would still go for the ZF50/1.4 as I did.
3.4K is a much better price than when it first came out.
2.8K, however, is a price when this Nokton first became available.