Tele 400mm ( maybe Sigma )

[Schmelzer]

Hi all, 

i am looking for information on the Sigma(s) 400mm f5,6, regarding the
optical quality. As I understand there are serveral versions ( Apo, Apo
Macro, non-Apo etc. ) of this lens. I saw one in a Shop last weekend und do
now have to determine whether I should buy this special lens ot not. The
Nikon 400 is far to expensive, but if I figure out that the used Sigma in
that shop is a good deal, I will take it.


Regards - Martin