Attack of the monster lens grrrrrrr, June 29, 2008

First, I just want to say... I waited most of my life to get to the point where I could take professional quality pictures. Now that I am there, it is indeed everything I wanted it to be. I'm loving this. :-)This lens came to me because I accidentally dropped my 75mm-300mm non-IS non USM lens in the Gulf of Mexico while shooting the sunset at Lover's Key State Park, Florida. Some would argue that I probably did this on purpose just because I was sick of the poor quality of that lens, and although I do share your sentiments, I assure I did NOT do that on purpose. It *was* funny in its own way, but after realizing just how much damage was done to the internals and realizing I'd have to replace it, I was in fact quite horrified. I will quickly say this for that lens - it CAN yield good pictures, IF you know how to work it. Keep your aperture around F13 and stick to bright light, and it will produce...BUTIt is NOT a pro lens, and it will NEVER be a pro...

If the answer is "Yes!" then buy with confidence. This lens dominates its niche. It delivers on its promises and is one of the classic white L lenses.I got this lens to supplement the 28-135 IS, but I've ended up rarely using it. In fact, Ive decided that there may be a better choice for many photogs.First let me begin by stating the obvious. Most images taken with this lens here and on online galleries like photosig or photo*net are taken at 400mm. Duh! I was hunting last weekend and took this lens along shooting animal pics from a blind. I set it to 400 and left it there. For wildlife and landscape shooters in particular, if the lens is going to be used at 400mm practically all the time, I think a better choice might be the 400mm 5.6 prime- costs hundreds less and sharper to boot. Going a step further, one sucessful wildlife photog I know recommends that if you are thinking about shooting wildlife other than birds, forego 400mm(prime or zoom)and get the...

Reviews of this lens on the web are mixed with some showing soft results, particularly at 400mm. This is likely due to wide variations in sample lenses. I decided to take a chance and seem to have gotten lucky. My copy, just received from Amazon (Build date of Oct 2005) produces fantastically crisp and contrasty images on my 20D at ALL focal lengths from 100 to 400. It's almost magical. The images are much sharper using the same f-stops than those from a 70-200 f2.8IS lens at 100-150mm and virtually the same at 200mm. Even wide-open at 400mm this lens is quite sharp. At 400mm, I've compared to a very nice Canon 400mm f5.6L prime lens, with and without 1.4X teleconverter. The images have virtually the same extreme sharpness and contrast if the zoom is stopped down just one one-third stop (e.g. zoom at 6.3, prime at 5.6). With the 1.4X TC both lenses had to be manually focused but produced outstanding clarity with NO perceivable loss in quality. The focus is swift and true and...