This was my very first purchase after getting my 10D. Not a bad lens but just not
sharp enough for my liking. At this point it was when I decided to make a move
to the L series glass which is produces excellent results.

------------------------------------------------------------------------------------------------------
Canon Website Description
Ultra-wide zoom lens with portrait-length telephoto capability. By having multiple lens groups move during zooming, the lens was made compact and lightweight. The Ashperical element suppresses distortion. High contrast is maintained at all focal lengths and sharp images are obtained.