I've been doing and enjoying some deviant street shots. I read Chris Walkers PDF and really dig his stuff, I cant afford the camera he uses and recomends so I'm usingthe trusty Nikon F-601 with a 30-70 lens Now he suggest a 30mm max and get in tight to the subject style approach. In this months Digital Photographer they have a section on Portraits and they are shot in the main (studio) with a 150mm. Some of my street stuff is a little small in the face, upgrade lens to large and its more intrusive and obviuos (sp?) Is the 150 really a portriat studio lens? Can you get good on the fly street with that size? Any thoughts?