I appreciate your reply. We have a competition next 11/18. I am thinking about renting a lens. Am looking at the Canon 70-200mm f2.8 is l , or the Sigma 18-200 mm f3.5-6.3 optically stabilized. I know there is a big difference in rental price and the Canon is more than likely better, do you think it is worth the extra money? Competition will be indoors, lots of high speed action. Having never used an IS lens, really don't know what to expect.Isthe Canon f2.8 @ 200 mm zoom going to be like night and day noticeable then the Sigma f6.3 @ 200mm?