I loved the 17-40L. It was my absolute favorite lens. The only reason I sold it was because I all but stopped using it when I got the 24L II. I mainly focus on landscapes for my photography and the 17-40L with its cheap price and excellent quality (both build and image) made it an instant smash hit in my backpack. The MFD is pretty close and at 40mm you can get some interesting perspective shots close up. I never noticed much issues with the sharpness of the lens as people usually comment on, but I never really look that hard at the photos either. I try to edit the colors and contrast how I want them and then resize for web viewing. This tends to reduce image quality and sharpness anyway. I was shooting JPEG while I had the 17-40L and didn't start shooting RAW until after I moved on to other lenses, because I bought LR5 at the same time as some new lenses. This was also the fastest focusing lens I have ever used. To this day I can't think of a lens that impressed me on AF speed like this lens did.
In the search for an ultra wide angle lens? The 17-40L is worth a look. Even with the new 16-35L lenses available, the low price point of the 17-40L makes it a fantastic contender for the UWA in your photo bag. And I can say the weather sealing works great! I've use it with my 5D2 at a giant rapid waterfall and in the rain, and really all around the Cascade mountains without any issues. If you haven't used an UWA and are thinking about getting one, go rent/borrow/look at the 17-40L. It is certainly worth a look.
This first example is of a lady bug at the MFD. Very small target, but it includes so much background making (for me) a very interesting take on an otherwise bland subject matter.
This was also MFD on a mossy railing.
[IMAGE'S LINK: http://i257.photobucket.com ...239/kawi_200/IY1Y0343.jpg] on photobucket
A few smaple lanscapes I have while driving around and taking pictures. The first picture does not do the lens justice. I just previewed the image and scaled down to 533x800 doesn't show the true sharpness the 17-40L is capable of. It lost a lot of detail.
[IMAGE'S LINK: http://i257.photobucket.com ...0Mountains/_MG_0692-1.jpg] on photobucket
[IMAGE'S LINK: http://i257.photobucket.com ...d%20Skylines/_MG_2361.jpg] on photobucket
[IMAGE'S LINK: http://i257.photobucket.com ...0Skylines/SunsetBlend.jpg] on photobucket
I'm not 100% if this was taken with the 17-40L, but I think it was.
[IMAGE'S LINK: http://i257.photobucket.com ...d%20Skylines/_MG_3980.jpg] on photobucket