I read somewhere of someone bumping ISO up to like 400 for sport shots. What if its a really bright day and you can get 1/640 lets say, and your at ISO 100, do you even need to bump is up to 200 to get a faster speed? It might be more than 1/640 on a hot day im just saying a random number. Lets pretend this is for soccer, and not nascar hehe... It seems people bump the ISO up just because sometimes. I dunno, any insight? BTW, Yes I know about ISO, so dont need to teach me how to use it Im more or less asking about other peoples techniques on ISO in sporting events.