Let’s face it:

When learning something new in life, there is always something that seems harder than it should, and ISO in photography is one of those things.

In this article, I will not only teach you what ISO is but how you can use it to get the best images you’ve ever taken.

Sound good?

Then let’s get started.

1. What is ISO in photography?

The first thing to understand about ISO is that it is the final component of exposure, the other two being aperture and shutter speed.

If you are feeling unsure about either of those, check out the links to read my awesome articles that cover each, in-depth.

Feel free to also check out my in-depth article on learning photography. This article can help you make sense and put together all of these components of exposure to help you become a better photographer.

iso controls digital sensor sensitivity

The digital sensor on a digital camera.

ISO is the setting that controls the sensitivity of the digital sensor light. As you adjust the ISO setting, the digital sensor becomes more or less sensitive to light, depending on how you adjust it.

When shooting with film, ISO is the sensitivity of film to light, and can not be adjusted. For you to adjust the ISO on a film camera, you need to put in a new roll of film rated to the particular ISO you seek.

ISO can seem complicated, but it really is not. Adjusting the ISO down, to a lower number drops the sensitivity of the digital sensor. When this happens, more light is required for the proper exposure of the image.

Changing the ISO to a higher number raises the sensitivity of the digital sensor. When this is done, less light is required for the proper exposure of the image.

LOWER NUMBER = LOWER SENSITIVITY TO LIGHT HIGHER NUMBER = HIGHER SENSITIVITY TO LIGHT