Summary: The only downside is that it doesn't have auto focus and there are no guides to help focus like there used to be in the old 35mm SLR lenses so you have to just "see" if the scene is in focus. Of course, if it did have autofocus, it would be much more expensive. Upside is the price.
Decent lens, but there's 2 versions it looks like.
4 December 2013
Summary: The lens offered appears to have changed alittle. When I bought it back on 3/13 there was no autofocus motor in the lens and was listed as model number A15. Now a new picture appears clearly showing an autofocus motor and the model listed as (A15N).
Summary: Excellent image quality, easy to use. Price is so low from KEH you will be immune from buyer's remorse. With Nikon mount, this lens requires camera with focus motor screw drive in mount for auto focus. Manual focus works on all cameras.
Summary: A friend recommended this brand of lens for my Nikon after she purchased one through National Camera at their recommendation. I am glad I took her advice. This lens is far less expensive than the Nikon brand lens and works just as good.
Good product for the price especially for somone starting out on a budget
14 January 2013
Summary: Contrary to what several others reviewed, this is an autofocus lens if you've go the camera that will do it. Running on a Nikon D800, it works fine, a little noisy, but you get what you pay for. On my 3100 its strictly a manual focus lens.