White balance is one of the most important settings on any camera. It can make the difference between vibrant, accurate colors, and a muddy, flat mess. It is also the setting least likely to be tweaked manually by casual photographers. There’s not even a good way to adjust white balance in the iPhone’s own Photos app.

But don’t despair. Today we’ll learn everything you need to now about how white balance works, and what to do with it.

For most photos, the iPhone camera proves perfectly adequate. You just hold up your phone, point it, and shoot. The exposure and focus are almost always correct, or at least correct enough. But on occasion, you need to take control.

For instance, maybe that beautiful dark blue sky keeps getting washed out because the iPhone insists on correctly exposing the face of the human in the foreground, when you’d prefer to see the person in silhouette. (Or vice versa.) Or perhaps the iPhone insists on focusing on that tree in the foreground, instead of the person half-hidden behind it?

Both of these can be fixed using the manual controls built right into the iPhone’s own Camera app. They’re pretty well-hidden, so you might never have even noticed them. But rest assured, they are there — and they are very easy to use!