Now this is a turnup for the books. As I read about the 19 f2.9 for Nex and m4/3 mount I immediately thought of the Sigma lenses I used on my Canon cameras. I swore I would never touch a Sigma lens again. Well, after reading all the reviews and looking at a lot of images on the internet I just couldn't say no, so I ordered one. To tell the truth this is one very nice lens. Very surprised. Although it is a little warm (like all Sigma lenses) it does produce sharp contrasty images. Build quality is okand focusing is quiet and fast.