What is Aperture and How to Use It in Photography

If you’ve ever picked up a camera and wondered why some photos have that dreamy blurry background while others keep everything sharp from front to back, the secret often comes down to aperture.

What is Aperture?

Think of aperture as the “eye” of your camera. Just like your pupil gets bigger or smaller depending on how much light is around, the aperture in your lens does the same thing. It’s simply the opening inside the lens that controls how much light gets in when you take a photo.

A big opening lets in a lot of light, while a small opening lets in less. Easy, right? But aperture doesn’t just control brightness — it also changes how your photo looks.

Why Does Aperture Matter?

Here’s where it gets fun: aperture affects something called depth of field. That’s just a fancy way of saying how much of your photo is in focus.

• Wide aperture (big opening): This gives you a shallow depth of field. In plain English, it means your subject is sharp but the background melts into a beautiful blur. Perfect for portraits where you want the person to pop.

• Narrow aperture (small opening): This gives you a deep depth of field. More of the scene, from front to back, stays sharp. This is great for landscapes where you want everything from the rocks in the foreground to the mountains in the distance to be in focus.

How to Use Aperture in Your Photography

The easiest way to start experimenting is to switch your camera to Aperture Priority mode (A or Av on the dial). This mode lets you choose the aperture and the camera takes care of the rest.

• Want dreamy portraits with blurred backgrounds? Try a wide aperture like f/2.8.

• Want a sharp landscape? Go for a smaller aperture like f/11 or f/16.

• Shooting in low light? A wide aperture lets in more light, which can help keep your photo bright without needing a flash.

A Simple Way to Remember It

Big number = small opening = more in focus.
Small number = big opening = blurry background.

That’s really all you need to know to start using aperture creatively in your photos.