Your camera has many different modes, many of which you’ll probably not even look at. Each of them is designed to help you out with one or more shooting situations.


Aperture priority mode is one of the main shooting modes on most digital SLR cameras. You can find aperture priority mode by twisting your camera’s top dial to the letter “A” or “Av”. If you have a point-and-shoot with an aperture priority mode, the symbol might be different so check your manual.

Once you’re in aperture priority mode, you can only adjust one variable on your camera – the aperture.

The aperture is the hole through which light enters to paint a picture on the image sensor of your camera. The way you adjust it can have a major impact on the pictures you take. By making some small changes, you can create sharp landscapes and distraction-free portraits.


When the aperture is open it takes in more light, this is a great advantage when taking pictures indoors or in low light situations. Instead of using flash, you can simply click the shutter and use the natural light available to you.

However, as the aperture opens you get less depth of field, which means there is blurring in front of and behind your main focus subject. This isn’t important when taking portraits because the background usually isn’t that important but it can become a problem when taking a picture of a landscape. When you look at a landscape you want to see the whole landscape in focus which isn’t possible with blurring.

How does aperture priority mode work?

When you set your camera to aperture priority mode, you get to pick the aperture and the camera picks the corresponding shutter speed. Your camera uses its internal light meter to figure out how long it will expose the image sensor to light, creating what it “thinks” to be an even exposure.

It’s very similar to automatic mode, but you get a little bit more control. By controlling the aperture you control the depth of field, the amount of the scene that remains in-focus. If you pick a very wide aperture like F4, the scene will have a shallow depth of field, and the camera will automatically pick a shutter speed to go with it. The camera has to increase the shutter speed because the wider aperture is letting in more light.

If you were to pick a more closed aperture, say F22, the scene will appear much sharper. The camera will then have to pick a slower shutter speed to allow more light in.

It’s a good idea to play around with aperture priority mode so you can see exactly which aperture and shutter speed combinations it’s coming up with and in which situations. Watch how, as the aperture’s f-number increases, the shutter speed decreases. Knowing this will give you a good starting point when you put your camera on manual photography for the first time.

Shutter Priority Mode