Along with the 16-35mm f/4L IS USM lens, Canon has also introduced a budget wide-angle lens for its EF-S mount, the Canon 10-18mm f/4.5-5.6 IS STM. At a very compact size, image stabilization and just 240 grams of weight, the Canon 10-18mm will be an interesting choice for Canon’s APS-C line of cameras like 7D, 70D and Digital Rebel series. With an equivalent field of view of 16–28.8mm relative to full-frame, the lens will offer great ultra wide angle coverage. And with its MSRP price of just $299, it will be a great choice for beginners and enthusiasts interested in landscape, travel, architecture and everyday photography.
The biggest drawback of the lens is its limited maximum aperture range of f/4.5-5.6, which is pretty slow. Most lower-end lenses start out at f/3.5 on the wide side, so the f/4.5 aperture is rather unusual and limiting. However, with the added benefit of image stabilization that provides up to 4 stops of shutter speed improvement, one could more or less negate this 2/3 of a stop disadvantage.
As for the lens performance, it seems to be a pretty solid lens according to the MTF charts provided by Canon:
In its current line of EF-S lenses, Canon has been offering the EF-S 10-22mm f/3.5-4.5 USM lens since 2004. However, at its MSRP of $649 and lack of IS, it makes the new 10-18mm look like a great bargain.