SLR Gear, the reviewing arm of Imaging-Resource for things other than bodies, has apparently begun reviewing IS systems. So far, they’ve hit Canon’s budget L classic, the 70-200 f4 IS, and Olympus’ rather successful E-520 with its in-body IS. Two different IS systems, both toting great and wonderous amazing things. Their conclusions? Neither live up to their full marketing hype, but both seem to do the job they set out to do admirably nonetheless, pulling up to 2.9 (let’s call it 3) stops of sharpness back.

Again, we’d like to remind those of you without much IS experience that it works by countering for how your hands naturally shake at long expsures, IS can’t restore sharpness lost to moving subjects at long shutter speeds. Its use in low light is primarily architectural, if you’re looking to shoot parties and bars you’ll still need higher ISO, faster lenses, or a good flash gun.

Read their findings and whitepapers on IS testing here: http://www.slrgear.com/articles/index.html