Boost ISO to Increase Depth

A higher ISO setting means the camera is more sensitive to light and will result in the camera selecting a faster shutter speed and/or a smaller aperture. On cameras which don't allow manual control of shutter speed and/or aperture, the only way to changeeither may be via changing the ISO.

So, for example, if you want a higher shutter speed to stop action, one way to get itcould be to set the ISO to a higher value.

Similarly, if you want to maximize the depth of field for macro work, you need a small aperture. This can often be achieved on all-auto cameras by choosing thea high ISO--say, ISO 400 instead of ISO 100.

The examples shown here were shot with the same camera at the same focus setting under the same lighting conditions in program mode. The only difference was the ISO chosen. As you can see, at ISO 400 the camera chose a smaller aperture (f/6.7 vs. f/2.8), which resulted ingreater depth of field.