Lens on tripod, AF, IS mode 1. The difference is not that significant at 70mm, but the image with IS on with 2 sec delay is still the sharpest. Definitely the IS helps to get a sharper image even at slow shutter speed and on tripod with remote cable release. If the shutter was fully pressed before the IS had a chance to stablize(i.e. no 2 sec delay), it would result in blurry image, which may be due to the IS mechanisms or simialr to situation when the IS was turned off.