I was playing with ISO settings at Leo's basketball game. In order to get a fast enough shutter speed so as not have a bunch of blurry basketball players, the minimum I seemed to be able to use was ISO 1600 (top photo). This is grainer than I like, and bumping the ISO to 5000 (bottom photo) was even worse. My camera's ISO setting go all the way to 25600! I don't know when I would want to bump it that high, but lots of folks must do it since it's a setting on the camera. I have learned to set my ISO manually as my camera on auto ISO bumps it much higher than I like.