Most people tend to think of image stabilization as being mainly for telephoto lenses. While it's true that their longer focal lengths tend to magnify the effects of camera shake, image stabilization can provde a very useful assist at wider angle focal lengths as well; anyone who's ever tried to blur the image of a waterfall, while keeping the surrounding landsape tack-sharp knows exactly what I'm talking about.
The Canon 400mm ƒ/2.8L IS II USM is promoted as offering four stops of image stabilization, but this is provided you can hold almost nine pounds reasonably steady to begin with. In our testing this is more or less the case: with stabilization off, we were getting solid results at 1/1,000 of a second; with stabilization on, we were getting a good number of shots at 1/60 of a second. There were a few less at 1/125 of a second, but that's what comes from hand-holding 8 1/2 pounds.
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| Mouse over this chart to show results with IS activated. |
IS systems tend to provide more benefit to less-stable shooters than very steady ones, so most users will see the same or greater amounts of shake reduction as we measured here. You can read more about our IS test methodology here: SLRgear IS Test Methodology, v2.
