Higher ISO = Increased Grain

One advantage to increasing your ISO setting is the ability to photograph in lower light without using flash.  However, doing so will most likely result in increased graininess in your images.  Higher ISOs (especially in later model cameras) give an image a foggy, fuzzy look.   

Graininess is not all bad.  In fact, some photographers purposefully choose a higher ISO with the goal of increasing the grain to creating an old-time feel to their image.  Graininess can also give an image a romantic feel.  Remember those old Hollywood portraits?

With the newer SLR models coming out, grainy images at higher ISOs are all but a thing of the past.  In order to get that dreamy, grainy, romantic look photographers will now have to turn to editing software. Chances are, however, that most of you won't own one of those cameras any time soon, so I thought a little "visual" was in order to help you see the affect ISO has on your images. 

Below are three very similar images all shot at different ISOs.  The first image was shot at ISO 100, the second at ISO 400 and the third at ISO 1600.  You can really see the grain in that last image.  If your goal is crisp and sharp images, shoot at the lowest ISO possible.  If you like the softer look of grain in your images, shoot at higher ISOs.  Just remember to adjust your other settings accordingly.

ISO - it's really just another tool to allow your creative juices to flow.