Yeah, but to get an equivalent field of view at an equivalent speed, you're stuck with a wide angle design for a normal lens, and an ultrawide for wide angle. This introduces size and expense and has tradeoffs in quality and speed.
Yeah I know. I have an XS (yes, I know it's a cheap body, I want to upgrade to the 60D) and with the kit lens the 18mm "wide" angle becomes ~28mm because of the 1.6x crop factor.
Thing start to work in favor of the smaller sensor once we start talking telephotos, tho...
I'm pretty sure they made the 7D just for this, because it shoots 8 FPS but has a crop sensor so it would be ideal for sports, wildlife, etc. Like I said above I have the XS but my 200mm becomes 320mm with the crop factor.
- All the glass worth owning is designed for full-frame - smaller DSLR formats get slow and/or soft zooms and a smattering of primes in useful focal lengths at useful.
Canon's EF lenses are designed for full frames but can also be mounted on APS-C crop sensor bodies. EF-S is meant for crop sensor bodies, therefore cannot be mounted on FF's.
On the eighth day, God created FORTRAN.