I'm looking for a good lensfor a 50D (only havethe kit lens today the 28-135mm f/3.5-5.6) to help with indoor Basketball pictures. I've been looking at the 85mm f1.8, the 100mm f2, and if I can find the money maybe even the 135mm f2. However none of these have IS such as the kit lens I'm used to. I've thought of getting a monopod to help, but my assumption has been that I will probably increasing my ISO to get higher shutter speeds, and therefore IS which helps with the camera motion will not be required??? Is it a fair assumption that above certain shutter speeds IS is not required?