Adam Gifford , Aug 26, 2009; 08:41 a.m.
The whole reason for EF-S was to make wide angle lenses for crop sensors, you should really reconsider.
To get really wide on a crop sensor, you need something that starts in the 10mm range. The canon 10-22 EF-S is a very good example of this range.
3rd party lenses that start at 10 or 11mm may be "EF" mount, but they only project an image circle for a crop sensor anyway, effectively making them EF-S.
Not to mention 10mm on a crop and a full frame sensor would be drastically different.
If you want wide on a crop, buy the 10-22, and sell it when you move up to full frame, and then buy a 17-40 or 16-35 EF. But these lenses won't get you really wide on a crop sensor, so don't buy the yet.