Understanding ISO: A Simple Explanation of How ISO Works and Why Increasing It Creates Noise

Ever wondered what’s actually going on inside your camera when you take your ISO from 400, to 800, to`1,600 and so on? If you’d like to find out, this straight-forward explanation by Ian Gibbons of PanvistaProductions from 2012 does a great job of explaining the electronics behind the exposure.

Gibson starts off by explaining how a digital image sensor works (on a very basic level) before diving into what exactly happens when you increase your ISO setting. He then explains what noise is and why, when you crank up your ISO, it becomes increasingly apparent in the image.

It’s not groundbreaking stuff, and someone like Roger Cicala with his deep technical knowledge and curiosity about a camera’s inner workings probably won’t get much out of it, but beginners and photo nerds in-training will definitely learn something.