How to Understand F-Stops on a Digital Camera

Learn about F-stops from commercial photographer Dan Bracaglia in this digital photography lesson from Howcast.

So assuming you’ve already learned what aperture is, I’m going to talk a little bit about what F-stops are. F-stops a numerical scientific value assigned to various openings in a camera lens in the physical aperture. And they go like this, these are full stops. It starts at F1.4, goes to F2.8, F4, F5, F6, F8, F11, F16, and we’ll stop at F22 because most lenses don’t go much higher than that.

So what do all these numbers mean? What it really actually breaks down to is an algorithm about light refraction and how light’s passing through and it gets really kind of scientific and confusing. It’s really not that important. Just knowing the values of the F-stops though is really important. And there’s stops in between each of these. There’s half values, like in between F1.4 and F2.8, there’s F1.8 and F2 and F2.4.

If you look at any lens, a lens like this for instance, it has the same exact F-stops written out right on the lens barrel. Now, if you were using this on an old school camera, you would physically stop down or stop open the aperture using the style here. On newer cameras you don’t. This is physically opening and closing down.

F1.4 is going to look something like this. It’s going to be completely opened up. You get to F2.8, it’s going to be a little bit smaller. The F4’s going to be a little bit smaller. F5.6 is going to be a little bit smaller. And so on and so forth, until you get to somewhere around F22, which is a really tiny opening. F1.4, the most light is going to come in. You’re going to have the opportunity to have a fast shutter speed. F22 is going to be the least amount of light coming in. You’re going to have to have a very long, well just a much longer shutter speed than if you’re at F1.4.

And this is just some advice to help you understand the numerical values of F-stops and how they relate to your camera and exposure.