Conventional wisdom says turn the IS off when using a tripod. The question is which is better (Off or On) when using a monopod where some shake is likely. This single composite shows center cuts from shots made with an Olympus E-510 and using a Manfrotto monopod. The lens used is the Olympus 50-200mm and the shots were at 1/50s. My conclusion is to leave the IS on when using a monopod. Both shots were sharp in either case but both the 100mm and 200mm shots with IS On show just a bit better highlight detail. I've added 5 shots. All were made at 200mm, 1/30s using shutter priority. The exif information tells the rest. The last is a composite of all four shots. Which shot goes where in that composite is left as an exercise for the viewer!