Originally posted by paulh The DA 16-45/4 is one I'm interested in - how does its sharpness compare with the other lenses mentioned?
When I was doing my research into this range of lenses, the DA 16-45 was beaten in IQ by the Tamron 17-50 according to users on the internets. Since I can't find many testing data* between the 16-45 and the Sigma/Tamron 17-50s, I can only go by online testimonials. Most of the testimonials, however, stated that it was only a small margin that the DA 16-45 lost by, but the slower speed (1 stop) was the killer for them.
So, if you don't mind the slower 16-45, it's still very good.
*I use testing data comparisons from Lenstip, photozone, or The Digitial Picture ISO tests.