I'd read all of the great reviews of this lens and ordered one.I compared sharpness of the 24-105 to my Canon 17-85, 70-200 F2.8IS and the tamron 28-75. All three of these (YES EVEN THE 17-85), absolutely exceeded the 24-105 in contrast and sharpness. The 24-105 was not even close to the other three. All were shot at F5.6 at about 75-80mm. The 24-105 looked like a $100 lens compared to the other three!That copy is on it's way back to Amazon. I'm hoping that it was just one of those infamous 'bad copies'.COMMENTS added 08May2006: I received my second copy of the 24-105. The sharpness and contrast of the second copy are equal to that of the 70-200 F2.8IS. If you are planning on buying this lens, test it to make sure your copy is truly of "L" quality!

Upgraded from my kit lens (18-55 IS) that came with my Canon T1i. I haven't even looked at my kit lens since. Fantastic! The pictures have so much more contrast, and so much sharper. Now I fully understand why my new lens (24-105mm) cost more than my camera kit (body & lens). If you are unsure on purchasing, let me just tell you, I am a newbie hobbyist photographer and I love it. Just be prepared, it's noticeably heavier than the kit lens, or even the 55-250 IS EF-S lens. After hiking Glacier National Park with it, I will never let it go. Hope this helps your decision.

I am a professional portrait and wedding photographer and recently purchased this lens. It has now become my primary lens for shooting. Love it, great focus and quality. Very nice, sturdy lens.

After trying and trying and getting only lousy images, I sent this lens to Canon for a service. I was told "an adjustment of the circuit board was incorrect causing the focus to operate incorrectly"I received my lens back and, $290 later, got the same poor images: not sharp, almost hazy.I sent it back again and it was returned with the following comment: ��lens assembly line did not operate correctly causing the focus to operate improperly��.Either it wasn��t fixed the first time or the product is flawed by multiple recurrent structural problems.Canon would not replace the lens.Would not buy again and extremely disappointed with Canon customer service.

Besides its image quality, build quality and the IS feature, the best thing I like is its wide range. I don't need to carry my 17-40 and 70-200 in many cases, and even if I do, I don't need to switch lens that often.However, if I don't plan to go full frame in near future, maybe I will buy the new 17-55 f2.8Anyway, it is a great product if it fits your needs.

This lens has been my go-to lens for nearly 3 years now. It is a great out door lens or whenever you have plenty of light. The 24mm on a 5D full censor makes for great wide shots. Don't be fooled by it's f4.0 when shooting video however. I have found that it produces an awful video image at f4.0 and will NEVER look in focus no matter what you do. The lowest you can go is f5.6 to get a clear image. Very disappointing. The sooner you learn that the less work you destroy the minute you capture it. I wouldn't pay the money for it again knowing what I know.