Filming, tripods, long lenses and IS

We're all aware that IS is a wonderful invention whether you're shooting stills or video. However, there is one caveat to that - when using a tripod.
Most of the recent IS lenses don't require you to turn off the IS when you mount the camera on the tripod, however in our experience, if you're pretty certain the setup is stable, then turn it off otherwise you'll end up with slightly blurry images as the shutter speed drops.
For filming, you don't end up with blurry images. From our experience, we've seen that with longer lenses when filming from a tripod, you don't so much get blurry images, as motion in the images - in other words the image seems to drift back and forth as the IS spins but there is nothing to correct. Essentially the IS elements that move to counteract are creating a movement that isn't there. To avoid this, simply turn the IS off when you put a big lens on a tripod and plan to do some filming.
Look out for a post early next week where I'll put up two video clips, one with IS on and one with IS off to show the effect...

-blabpictures-