One and all: I'd have to differ on the merits of IS, having recently moved from Pentax to Canon for my main photo system. I own the 28-135 IS and 100-400 IS zooms. My son, a bird photographer, owns the 300/4 IS. (You Oregonians on the list can see some examples of his work in the current issue of Oregon Coast magazine, where he's got an article on backyard birds. All the illustrations were shot with the 300/4 IS handheld with 1.4 extender, generally around 1/90th of a second exposure. Try that without IS....)
With all three lenses, you trade a few ounces of extra weight in the lens for the freedom from a few pounds of extra tripod. While they do make a soft whirring sound, none of the Canon IS lenses is as noisy as regular Pentax autofocus. After watching my son work with the Canon system, I was persuaded. I didn't ditch all my Pentax equipment, however, as I like the manual bodies' compactness and heft. -- Bob Keefer Keefer Photography (541) 914-9259 www.bkpix.com
