I just ordered this lens for the *istD for shooting toy train shows. It'll be my first zoom lens. My expectations are only that it not be horrible, and if it's better than that then that's a bonus. I picked this lens because it covers the same range as the three primes I've brought to train shows in the past (28, 50, 77, for 35mm film camera), it's barely larger than my 50 1.4 so it'll be unobtrusive, and it's cheap.
Its other potential purpose is as my walk-around lens, though the *istD may be large enough that I just never do that. My P&S may live on in that role. Has anyone used this thing? http://www.sigma-photo.com/html/pages/18_50_DC.htm Amy
