Pros and cons How to use ISO to help achieve your best shots
Control ISO and aperture, shutter speed will follow
ISO is the new kid on the block when it comes to creative control of your images. With film photography, the only control you had over ISO was deciding which speed film to load. Short of swapping films around, that was pretty much it.
However, with digital photography, ISO is a full member of the exposure trinity, so you can change ISO for every picture you take, if you feel that way inclined. Balancing three settings might not appeal, but you can task the camera to do the work for you with Auto ISO, or you can assess the light and dial in changes manually. The choice is yours.