Aperture Priority Mode

For some new photographers, manual mode seems overly complicated. One way to ease your way into your camera’s manual controls is to use aperture priority mode. This mode is great for beginners who want to understand aperture, but even experienced photographers often use aperture priority mode for certain conditions. Learn more about how and when to use this mode in order to change the look and focus of your photos.


Yashica love by 55Laney69
Aperture: f/1.8

Aperture Explained

Before you switch to aperture priority mode, it’s important to understand aperture’s role in photography. Essentially, aperture refers to the hole inside a lens that lets light into the camera. The aperture can be made smaller or bigger to allow more or less light onto the camera’s sensor.

Aperture is measured in f-stops, with larger numbers referring to smaller openings, and smaller numbers referring to wider openings. Each f-stop is a doubling or halving of the amount of light allowed into the lens. For example, f/8 allows in only half as much light as f/5.6.

A lens’s maximum aperture is indicated somewhere on the lens with an f-stop number. A 50mm f/1.8 lens, for example, has a maximum aperture of f/1.8.

Depth of Field

In addition to affecting how much light is allowed to hit the camera’s sensor, aperture size affects the depth of field. Depth of field refers to the part of the image that is in sharp focus. Large apertures result in a narrow depth of field that puts only a sliver of the picture in focus. The larger the aperture size, the smaller this range of sharpness.

The out-of-focus part of the image that results from using wide apertures is called bokeh. Bokeh, which comes from the Japanese word boke, means blur or haze. You can maximize bokeh by using the widest aperture possible and increasing the distance between your subject and the background.


3+1+5+1+4=BOKEH by Kenny Louie
Aperture: f/2.8

Small apertures have the opposite effect. Landscapes often benefit from a wide depth of field, which is achieved by choosing a small aperture (larger number). This renders more of the photo in focus from front to back. By choosing a very small aperture, a photographer can keep an entire scene in focus–from objects near the camera to objects far in the distance.


Machu Picchu, Peru by Pedro Szekely
Aperture: f/20

Aperture Priority Mode

Aperture priority mode, most often indicated on a DSLR mode dial as A or Av, is a semi-automatic mode that lets you choose an aperture size while the camera chooses the shutter speed and ISO in order to make a technically correct exposure. As you change the aperture, the camera continues to make changes to the other settings automatically.


Fruity-Loops by Sherman Geronimo-Tan
Aperture: f/2.8

When you use aperture priority mode, you decide whether you want the entire image completely in focus, just one part in focus with a blurred, unidentifiable background, or a small part of the image in sharp focus with a slightly blurred background so the viewer can still see some context. After choosing the aperture setting, you can devote all of your attention to composing the image.


Buckman Coats 1 by Conor Ogle
Aperture: f/1.4

When to Use Aperture Priority Mode

Aperture priority mode is a useful option for new photographers who are just learning about camera settings and exposure. It takes away the stress of controlling other settings while giving you quick feedback about how aperture size impacts your pictures.

It’s also a useful mode for times when you’re photographing in rapidly changing light conditions or when your subject is moving into many different lighting conditions. You might be photographing a child playing and moving in and out of shade, for example. The camera will continually re-adjust its settings to match the lighting.

When depth of field choice is more important than the shutter speed, aperture-priority mode is an easy solution that lets you pay as much attention to your subject as possible without having to fiddle with camera controls.


Aperture priority mode is not without its limitations. Watch the shutter speed as you’re shooting. If your aperture is too small for the lighting conditions, a shutter speed that is too slow for hand-holding a camera may be chosen by the camera. Be sure to use a tripod in these instances or switch to a wider aperture to allow more light into the camera. Many cameras are equipped to send a warning when the shutter speed gets too slow for hand-holding the camera. This is usually denoted by a blinking light when shutter speed drops to somewhere around 1/50 of a second or slower.

If a photo appears to be over- or under-exposed, use exposure compensation to override the camera’s automatic settings. Exposure compensation is usually controlled using a camera button with a +/- symbol. Consult your user manual to get instructions for your camera model. A technically correct exposure, according to your camera, puts the meter at an exposure value of 0–right in the center of the meter. If you want to make the photo darker or lighter, you set exposure compensation above or below zero. For instance, if your photos are coming out too dark, you could dial in an exposure compensation of +1. Exposure compensation gives you more control over your image’s final outcome.


Wonder by Daniel Zedda
Aperture: f/2

Get a step closer to understanding manual mode and gain some creative control of your images by setting your camera’s dial to aperture priority mode. You’ll quickly learn how aperture size affects your photographs and get just the right part of your image in focus.

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Profile photo of Nicoal Price About Nicoal Price

​Nicoal is a New England photographer with a penchant for learning. Her work ranges from nature-inspired portraiture to outdoor product photography. Visit nicoalprice.com for more info.

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