So a quick little recap on what ISO is… I often refer to ISO as fake light. It is basically a way to brighten a photo after you have already set your aperture and shutter speed. Or in other words, it is how much light your camera will put into the digital print of your photo. Unlike shutter speed, it will not slow down how fast your camera is taking the photo and unlike aperture, it does not change your background.

Now, this seems like it should be the perfect setting and is too good to be true, and it kind of is. Like anything you can overdo it. So the downside to ISO is the higher you set it the grainier/noisier your photo will be. That does not mean that you should not use ISO at all but rather that learn how to use it well. It is a very useful tool and it seems like it is often one of the last things that a photographer will learn how to use well.

One of the first things to keep in mind is that each camera is different and will handle ISO differently. For instance, on my camera, I would not use an ISO higher than 1600 while other cameras do just fine at 3200+. When setting the lighting on your camera first change your aperture and shutter speed before changing ISO. This will allow you to set your ISO as low as possible.

The last thing I want to cover is how to use ISO when you are wanting a grainy or slightly retro-looking photo. This is not often done but if you turn your ISO up quite a bit you will get the grainy look. And of course, whatever aesthetic you are going for the more you practice using ISO the better you will get.