I remember reading or probably was told that you should turn off the IS function when shooting on a tripod. Since I generally keep the IS turned on on both of my two IS lenses (EF 24-105mm f/4L and 100-400mm f/4.5-5.6L) as a default, I suspect more than once I have left it on while on a tripod. So far, I haven't noticed any problems. What will happen if you leave on the IS while shooting on a tripod? Will it just effect the images, or will any harm come to the Image Stabilization in the lens? Does this same general guideline apply to the use of a monopd?