lovelifey: [Photography] Aperture Priority Mode: The Ultimate Guide

The post Aperture Priority Mode: The Ultimate Guide appeared first on Digital Photography School. It was authored by Kunal Malhotra.

a guide to aperture priority mode (plus tips)

What is Aperture Priority mode? And how can you use it to capture well-exposed, artistic images?

In this guide, I explain everything you need to know about Aperture Priority, including:

When it’s useful (and when it should be avoided)
How to adjust your camera settings while using Aperture Priority
How to handle common Aperture Priority mode scenarios

So if you’re ready to take control of your camera and become a settings master, then let’s dive right in!

What is Aperture Priority mode?

Aperture Priority mode, often represented as “A” or “Av” mode, gives the photographer control over the aperture and the ISO, while the camera selects a corresponding shutter speed.

In other words, you get to determine your ideal aperture and ISO based on artistic and image quality concerns. And then your camera will choose a shutter speed that produces a well-exposed, detailed image.

Aperture Priority is a semi-automatic camera mode. It doesn’t offer full control over camera exposure settings, but it does let you adjust key settings. It’s designed to provide both flexibility and speed; that way, you can focus on the subject, composition, and artistry while the camera optimizes the exposure.

Aperture Priority mode variables: aperture, shutter speed, and ISO

If you set your camera to Aperture Priority mode, you immediately gain control over the aperture and ISO, while your camera takes control of the shutter speed – but what do these different settings offer, and why do they matter?

Together, aperture, shutter speed, and ISO are part of the exposure triangle. By adjusting any of the three variables, you consequently adjust the exposure (i.e., brightness) of the resulting image. However, when you use Aperture Priority mode, your camera automatically compensates for aperture and ISO adjustments by changing the shutter speed (with the goal of creating a spot-on exposure).

So if you widen the aperture, your camera will increase the shutter speed to compensate for the brighter exposure. And if you drop the ISO, your camera will decrease the shutter speed to compensate for the darker exposure. Make sense?

Here’s the bottom line: When using Aperture Priority, your camera will always try to maintain a good exposure, even as you adjust the aperture and ISO.

But you might be wondering: If the aperture and ISO don’t adjust the exposure, then why would I want to adjust the aperture? Why would I want to adjust the ISO? What do these two settings offer me?

Aperture and ISO produce three key effects:

By widening or narrowing the aperture, you can adjust the depth of field (that is, the amount of the image that’s in focus). A wide aperture (e.g., f/1.8) creates a very thin plane of focus, so most of the image blurs away. And a narrow aperture (e.g., f/16) creates a very deep plane of focus, so the entire scene remains sharp.
By increasing or decreasing the ISO, you can adjust the level of noise in the image. Noise appears as tiny speckles of color and light, and it obscures image detail – so by keeping the ISO low, you can maximize image quality.
By adjusting the aperture or ISO, you can force the camera to change the shutter speed. A fast shutter speed is essential for capturing action scenes (e.g., birds in flight or basketball players on the move), and by widening the aperture and/or raising the ISO, you make the camera boost the shutter speed. A slow shutter speed is essential for capturing beautiful long-exposure effects, and by narrowing the aperture and/or lowering the ISO, you make the camera drop the shutter speed.

So by making settings adjustments in Aperture Priority mode, you can improve image quality, add beautiful depth of field effects, and even add some long-exposure artistry.

waterfall photographed with a slow shutter speed aperture priority mode

The fourth variable: exposure compensation

As I emphasized above, Aperture Priority mode tells your camera to set the exposure (by adjusting the shutter speed) while you handle other image variables. And in general, the camera will do a good job and you’ll get bright, detailed exposures.

But camera exposure meters aren’t perfect, and there will be times when you want to deliberately overexpose or underexpose your images (often when photographing very light scenes and very dark scenes, respectively).

Now, you cannot adjust the exposure by changing the aperture, ISO, or shutter speed. In Aperture Priority mode, the shutter speed setting is locked – and a change in the aperture and ISO settings will be instantly counteracted by a change in the shutter speed.

That’s why cameras offer another setting, called exposure compensation. Exposure compensation is generally represented by plus (+) and minus (-) symbols, and it lets you instruct your camera to increase or decrease the shutter speed for a brighter or darker effect.

In most cases, you won’t need exposure compensation. But if you find yourself wanting to adjust the exposure, don’t be afraid to use it!

When should you use Aperture Priority mode?

First of all, Aperture Priority is a great mode to use if you’re a beginner hoping to better understand your camera settings. Because your camera will automatically select the shutter speed, you don’t have to worry about messing up the exposure – but at the same time, you can experiment with different apertures and see how your images change.

Plus, as you gain in skill, you can start to use the aperture to deliberately adjust the shutter speed and the exposure compensation function to improve image detail.

But Aperture Priority mode is also popular among professionals who have already mastered their camera settings. For one, if you don’t need to think about the shutter speed but you do care about the aperture, Aperture Priority will focus your attention on the settings that matter (and let you forget about the less-important shutter speed setting). If you’re conducting a portrait photoshoot in good light, for instance, Aperture Priority will let you adjust the depth of field without distraction.

Additionally, Aperture Priority, unlike full Manual mode, lets you react quickly to changes in lighting. For instance, if your subject moves from a shaded area to a sunny area, or if the sun comes out from behind a cloud, Aperture Priority will automatically adjust the shutter speed to compensate.

people moving from sun to shade aperture priority mode

In certain slower genres of photography, such as landscape photography, this isn’t especially helpful – but if you’re shooting action, reacting quickly to lighting changes is essential, and Aperture Priority can make a huge difference.

Here are a few genres where Aperture Priority is popular:

Portrait photography
Bird photography
Wildlife photography
Macro photography
Street photography

Of course, there is no single best camera mode for a genre, and you can always find photographers who work differently – but the above list is a great starting point.

How to use Aperture Priority mode: step by step

Working with Aperture Priority mode is simple.

First, set your camera mode dial to “Av” or “A.”

Next, set your preferred ISO (generally the lowest setting your camera offers).

Third, select an aperture based on depth of field considerations. In other words, if you want a deep depth of field, choose a narrow aperture. And if you want a shallow depth of field, choose a wide aperture.

Fourth, check your shutter speed. Is it fast enough for your subject? If you’re photographing sports, birds in flight, cars, etc., and you need a faster shutter speed, boost your ISO or widen your aperture.

And if you’re photographing moving water, moving clouds, or other moving subjects you wish to blur artistically, consider dropping your ISO or narrowing your aperture to decrease the shutter speed.

Next, take a test shot, and carefully observe the results. If everything looks good – including the exposure – then go ahead and keep shooting.

On the other hand, if your test image looks over- or underexposed, dial in a bit of exposure compensation, and only then begin shooting in earnest.

Handling common Aperture Priority scenarios

In this section, I examine some frequent situations where Aperture Priority mode can be helpful, and I share some settings advice.

Portrait photography

Aperture Priority mode is great for portrait photography because it lets you think about the depth of field while letting your camera handle the exposure.

Most portrait photos look great with a shallow depth of field effect, where the subject is sharp but the background is beautifully blurry:

Simply select a low ISO (such as ISO 100), then dial in a wide aperture. An f/2.8 aperture is a good place to start, but if your lens offers an f/1.8 or f/1.4 maximum aperture, don’t be afraid to widen the setting further.

Street photography

If you’re photographing on the streets of a busy city with a mix of sun and shade, Aperture Priority mode is your friend.

Choose a relatively narrow aperture, such as f/8, to keep most of the scene in focus. Then raise the ISO until you have a reasonable shutter speed setting (1/250s is a good speed to shoot for) in the shade.

That way, as you and your subjects move in and out of the shadows, your camera will make sure the exposure remains detailed!

Action photography

If you’re shooting birds, wildlife, or sports players, simply dial in a relatively wide aperture (such as f/5.6).

Pick an ISO that gives you a fast shutter speed (for many action subjects, 1/1000s is a good starting point).

Then, as the sun moves behind clouds, your camera will automatically adjust the shutter speed to compensate for the loss of light, and you’ll end up with beautiful images.