Everything You Need to Know About ISO, Noise & Color

“Light makes photography. Embrace light. Admire it. Love it. But above all, know light. Know it for all you are worth, and you will know the key to photography.”

— GEORGE EASTMAN, INVENTOR

It’s no mistake that we started this guide with a quote about light, because today’s topic (like most things relating to photography) is all about light. Specifically, how your camera reacts to light. ISO is the third — often overlooked — corner of the exposure triangle, and after reading this guide you’ll wonder how you ever got along without it.

We recently discussed the other two corners of the triangle in “Understanding Aperture: Controlling Light Based on the Exposure Triangle” and “Mastering Shutter Speed to Capture and Freeze Motion.” As with aperture and shutter speed, ISO plays a specific role regarding exposure and light, and a seemingly simple role at that. Simply put, increasing the number on your ISO will increase your camera sensor’s sensitivity to light, brightening your image. So then, if you’re shooting in a low-light situation and your photos are coming out underexposed, just increase the ISO level and brighten it up. Easy, right?

Yes and no. This would be a pretty short guide if that’s all there was to it… and you can tell by scrolling down, that isn’t the case. Adjusting…