Excerpt: Purchased this lens for football season and in the games that I have photographed so far this season, this is just what the doctor ordered. Brings you right into the action and is fast enough for most of the fields you will photograph at.
Pros: Consistent Output, Fast / accurate auto-focus
Excerpt: I use the lens for automotive photography and video. Stabilization is good and the lens is probably capable of far better shots than I produce. I try to be gentle with it and handle it with care. Every time I send it in to CPS for cleaning, it seems to need several hundred dollars worth of repairs (over $ last time). The velcro latch on the pouch broke, as did one of the zippers. Even though I've requested they be repaired by CPS, they never have done it.
Excerpt: Huge differences in results when zoomed at 200-300 mm at 6 ft compared to 400mm. (DOF issue) I have been using this lens to photograph my backyard birds. One very important leason learned is about sharpness of the photo and how shallow the Depth of Field can be when zoomed at 400mm at 6 ft from my birds. *** Don't confuse DOF issues with Sharpness. Much happerier now that I know.
Pros: Consistent Output, Durable, Fast / accurate auto-focus, Nice Bokeh, Strong Construction
Excerpt: Used this lens at a Canon live learning seminar and it was great, so ordered one from Adorama and they delivered promptly and in great condition. The sharpness of this lens while hand holding it is fantastic. I had a 170-500mm of another brand, but never could get perfectly sharp photos. Very pleased with this lens.
Excerpt: Very nice lens, great images. It's disappointing that it's not weather sealed. It's also disappointing that it won't autofocus on any but 1D-level bodies when using the 1.4x (or 2x) teleconverter. Zoom creep is customer controlled; you can tighten it up if you want, but that makes zooming tighter and harder too. The image stabilization works well but leads to a false sense of security. I got many blurry images when not paying attention to shutter speed.
Pros: Consistent Output, Rugged, Strong Construction
Cons: Blurry Focus, Lens Creep, Not Weather Sealed