« on: June 05, 2013, 09:37:48 PM »
My 100-400 is my principal lens. I do mainly wildlife photography and all of my photographs are handheld, shot while walking around. I don't shoot from fixed positions or blinds and I don't even own a state of the art tripod. For me, the 100-400 is the best solution. It's relatively light, relatively compact, and delivers (most of the time) very sharp images.
It's certainly not perfect. I find it to be unacceptably soft at apertures that are bigger than F7.1 and, honestly, it doesn't autofocus with a teleconverter. I'd love an extra 100mm. The predecessor to my 100-400 was a Sigma 150-500 which is, basically, a piece of junk, and I'd be the first in line if Canon came out with a 150-500 for less than $3000. But, as an all-round workhorse telephoto, it really can't be beat.