A lower ISO means less noise, greater dynamic range, and better image quality. As such, a lower ISO is almost always preferable — almost. ISO is only one of the three exposure parameters, and if you do not consider it in tandem with them, it can seriously affect your image quality. This excellent video tutorial will show you why you should not be afraid to raise your ISO when the situation calls for it.
[ Read More ](Originally posted by Alex Cooke)