I've been struggling in low light situations for a while now and I figured that a fast lens is the best solution as I'm unable to use flash in certain situations. I frequently shoot fast paced action (ie dance in low light), hence my shutter speed has to be faster too. So, how do I go about choosing one? I use a Nikon . I'd prefer to have a zoom lens. I'm looking for a mid range focal length, nothing too tele required.