Your camera collects and monitors light using three things: shutter, aperture, and ISO. These three light gathering functions work together to balance light in order to properly expose a photograph. To me, ISO is the person in a family who moderates and makes peace with every situation. If you are struggling to get the light just right with shutter and aperture, ISO comes along and resolves the issue… then shutter and aperture hug and make up.
If the photograph is still too bright or dark, use the ISO to fix it. Low ISO numbers let in less light and higher ISO numbers let in more light. A darker situation calls for a higher ISO number. A lighter situation calls for a lower ISO number.
The only thing you need to be careful about with the ISO is if you get your ISO too high, you will start to see noise in your photograph. Now, when I refer to noise, I’m talking about the grainy texture that will show up in the photograph. Noise can be fixed in Lightroom or Photoshop, however the photo will look a lot better if you can eliminate the noise in the field.
If you download the PDF I have created for you below, you can master the ISO next time you hit the road! Just click the “ISO” link below to download the chart. If you have any questions contact me!