Is the Sigma 17 50 mm f2.8 a good choice for Nikon D5100?

Is the Sigma 17 50 mm f2.8 a good choice for Nikon D5100?

If you need a lens with those focal lengths.

How do you know?

Follow this link to see.

http://imaging.nikon.com/.../index.htm

I hope you do know that only lenses with built-in auto-focus motors will auto-focus with your camera. Such Nikkor lenses have the prefix, AF-S.

If the Sigma lens has the letters "HSM" in its description, then yes it will.

It is compatible, with OS and HSM.
Here is a review
http://slrgear.com/...329/cat/31

While it does autofocus with your D5100, it does get some mixed reviews by users.
http://www.dpreview.com/...er-reviews

It gets a pretty good review from a professional.
http://www.photozone.de/...ma175028os

It's a great lens. I have this lens and it is tons better than the standard Nikon 18-55mm f/3.6~5.6.

http://www.althephoto.com/lenses/sigma17-50.php

Do you find that your 18-55mm lens isn't sharp enough or do you need the extra speed of the f2.8 lens?
If so then yes, it's a good choice. Don't forget that it will be quite a lot bigger and heavier than your standard 18-55mm lens.

If it is to replace your kit lens, you gain from the slightly bigger aperture size but then if you are after increasing your flexibility and range in shooting, no since the 17-50mm is practically the same as the 18-55mm lens.