Not everyone can or wants to pay the price on a Full Frame camera. So if you need to go extra wide on a cropped camera like the 7D or 550D / T2i, there's a few lenses that can help get you there. Most of which can run you somewhere around $800-$1000.00 bucks for a 16-35mm or maybe even a 17-55mm. Even the 10-22mm is a nice lens, but Sigma's got that beat with an incredible 8-16mm! Most of the time around that range you're talking Fisheye which isn't always so flattering for portraits, but this Sigma doesn't go there. New from Sigma and available for pre-order, It's possibly the widest lens available that isn't a Fisheye. Although it's not super fast sitting at F/4.5-5.6, but with Sigma's HSM built in, that range, and at this price point who are we to complain? Thanks Sigma. Not a bad price for this wide angle lens. Click here for prices on eBay.