Summary: Portrait lens? Not useful if you have a smaller studio. The problem is that this is a telephoto lens, so you have to be about ten yards or more away from your subject to even be able to take a decent portrait shot. Not a big deal unless your studio isn't in a spacious warehouse someplace and your range is limited. I wish I would have known that, but regardless this is an excellent addition to my collection and it will remain in my bag.
Summary: I bought this lens before going to a concert at a very small, intimate club that is known for insanely low light levels. It performed like a champ on my D7000. I was getting great shots while other photogs were grumbling obscenities. Since then, it's become my favorite lens for shooting high school volleyball games. Very fast autofocus, very sharp.
Summary: The results are from using this lens with my D800 FX 36mp body. This lens has way too much chromatic aberration at f/1.8 which very noticeable and takes away from the usefulness of the lens wide open. The lens shows a very good bokeh (out-of-focus blur). The sharpness is good. The lens is built well and adequate for general photography, just not outstanding; more suitable for low light photography when you need something faster than f2.8 in the short telephoto range.