Summary: Lens lock is for transporting only, but then again no lens creep. This lens is big; a little more than the diameter of a Pringles Can and about 8" long. Works with my CANON T3i but 200-300 focus takes a while, especially in LiveView
Pros: This is a 4 Egg Lens* (see cons) Has AF/MF, IS, and USM**. 70-300mm Telephoto Zoom Lens No lens creep.
Cons: *I bought it on Black Friday, Tuesday it was out of stock and they dropped it $100. It was back in stock on Thursday. -2eggs for New Egg **USM is pretty loud. Lenses rotate as you zoom and focus.
Excerpt: I bought one of these in 2006, intending it as a lightweight walkaround alternative to the 70-200mm f/2.8L IS. It had OK sharpness at first, but began giving unsharp pictures without stopping down after the usual knocking around.
Excerpt: I have owned this lens and used it during a zoological expedition to Sierra Leone on a Canon Rebel XT. Yes it's nice and compact and uses the same filter thread as the standard zoom but all my photos at the 300mm focal end were soft and with low contrast.
Excerpt: I bought it at B&H and returned it very quickly. Two issues (each is enough)1) It is hard to move. Especially, when the lens is pointed up. I found myself thinking twice before raising the leaden weight and forcing the lens to move. I just didn't bother with many shots.
Summary: If you search for reviews of this lens you'll find that the majority rate it poorly - take those reviews seriously! The only thing this lens has going for it is that it is small for a lens with this range.
Not worth the money, buy the 70-400 f/4-5.6 IS L lens instead
Mr. Shaun Pugh, Amazon
1 April 2012
Summary: I'm still deciding which lens to buy so I hired this lens and the 70-300 f/4-5.6 IS L lens and used them both for a week. They are both a very similar price, the L lens has a slightly wider aperture, but weighs more. Otherwise at least on paper they are fairly evenly matched.