Aperture Priority (AV) Mode

What is Aperture Priority in Photography? Why should you be using aperture priority? Do aperture priority or shutter priority mean the same thing? 

This article will be of use to you if you want to get off your camera’s Auto mode and take control with Aperture Priority [AV] or Shutter Priority [TV] mode.

In this article I am going to hopefully help you move Get Off full Auto mode and get going with one of your camera’s creative exposure modes. In order to do this I will be using static subjects. You can literally use anything from buildings to vehicles.

If you are a previous a student of my Get Off Auto workshop this article will be a great refresher.

What is Aperture Priority in Photography

Before we go any further let me start by explaining what aperture value [AV] actually is.

AV or aperture value controls two things, the amount of light entering the camera and the depth of field or the focal plane. If you look at the image of the command dial, this one is on my Canon 7D Mkii, you will see that you have several settings; [A] Auto, [P] Program, [TV] Time value, [AV] Aperture value, [M] Manual, plus 3 custom function modes.

What is Aperture Priority in Photography

What Is Aperture Priority [AV] mode compared to Shutter Priority [TV] mode?

AV or aperture value controls how much light gets through to the camera’s sensor. For example, at f2.8 the lens iris is wide open and lets the maximum amount of light through to the sensor. You might hear photographers talking about fast lenses. What they are actually referring to is the width of the lens’ maximum aperture.

TV or time value controls the speed at which the lens opens and closes in order to freeze any movement.

Your aperture determines the depth of field or depth of focus or focal plane. Now this isn’t as complicated as it sounds. If you compare some of the images contained in this article, you will notice that some are focused from the front to the back of the image whereas others have a distinctly blurred background, (otherwise known as bokeh.)

How blurred or detailed your backgrounds will look depends on several variables:

  1. your aperture, shown as f5.6, f6.3, f8 etc.
  2. the focal length of your lens, 50mm, 100-400mm etc.
  3. the distance from your subject

A large aperture, such as f1.4 will make your background look very soft. It’s also great for shooting in low light. A small aperture, such as f22, will extend the focal plane through the image.

The amount of light entering the camera is controlled by the iris:

lens iris

The size of the iris controlled by the aperture number. Conversely, the smaller the f number the bigger the iris. In the image below f/1.4 is the smallest f number but offers the largest iris opening, which equals more light entering the camera AND the shortest depth of field, (focal plane.) At the other end of the scale f/16 is the largest f number (in this example) which offers the smallest iris opening, which equals less light entering the camera AND the widest depth of field, (focal plane.) The focal plane is the amount of depth in the image which is in focus.

using aperture value - lens iris

 

Aperture is a great way to experiment with deep and shallow depth of field. It comes with many additional benefits that can make your photography stand out.

focal plane

This image of the bluebells on the Wrekin, has a wide depth of field or focal plane. You can tell because everything is in focus from the front to the back of the image. AV was set at f/16.

Bluebells on the Wrekin

Whereas this image of a dragonfly has a very narrow depth of field or focal plane. AV was set at f/2.8

Get off auto - Common Darter Dragonfly

Most photographers leave their camera on Aperture Value as it gives a lot of flexibility and control over the final image. In aperture priority mode, you let the camera do most of the work for you, however the camera will choose the correct speed and ISO based on your AV setting. You can also manually change your ISO, but this isn’t necessary. Your camera will automatically decide what shutter speed is suitable for a given situation. I purposefully chose the 7D Mkii because it is very good at higher ISO, which in turn allows me to shoot in poorer light.

Automatic Mode Equals Less Control

In automatic mode, the camera does all of the work for you. No matter what the light situation your camera will adjust automatically so that you get a usable image. The downside of using automatic mode is that it doesn’t give you any control over your pictures. You can’t control how sharp or blurred your images are.

This is a great way to take decent photos in any lighting situation. But to be honest it doesn’t satisfy my creativity. In this image of Haughmond Abbey ruins I set my aperture value to f/16, ISO 100, 1/125 sec (to get slightly blurred flowers.) If I had used auto everything would have been sharp and perfectly exposed, but I would have lost the impact imparted by the blurring of the flowers.

What is Aperture Priority in Photography - haughmond abbey ruins

Using Aperture priority mode is something that most professional and semi-professional photographers use in their work. Client requirements vary, some want their backgrounds to have a specific amount of bokah, (background blur), where others want to capture as much detail as possible using a wide focal plane. Using Aperture priority mode is perfect for you if you fit into this category of photographers.

When Should You Use Aperture Priority Mode?

Your camera comes with a variety of modes so that you can choose the appropriate one for certain situations. Here are a few instances in which you can make the most of it. There is always a choice between aperture priority or shutter priority.

To Achieve a Fixed Depth of Field

A fixed aperture means a fixed depth of field. This means consistent photos, which can be very important in some situations for some clients. I nearly always have my aperture wide open because I need that narrow focal plane to make my subjects pop from the background. Even at the far end of my 100-400mm lens, using f/5.6 still gives me a relatively narrow focal plane or depth of focus. I would imagine there is only about 6″ in front of and behind this Red Kite which is in sharp focus.

What is Aperture Priority in Photography - red kite on ground

Using Aperture Priority mode as a Beginner

As a beginner, you will no doubt find controlling the camera in manual mode overwhelming. Not only is  switching to different shutter speeds, apertures, and ISO values very time consuming but it can be very stressful. Sometimes you will need to choose between aperture priority or shutter priority modes, depending upon the circumstances. Having a good working knowledge of what is aperture priority in photography will only help you to capture better images.

Aperture priority mode is a good first step up from automatic mode. It lets you understand how to use depth of field creatively while the camera take away the other elements required to produce a well balanced shot. It can help you get ready for manual mode and introduce you to different aperture settings at the same time. If you would like to learn hands on how to use AV and other modes then you might be interested in attending my Get Off Auto workshop.

Experiment With Different Apertures

As a fully qualified teacher I understand that the best way to learn is by getting things wrong. As a beginner, having a good working knowledge of what is aperture priority in Photography is vital. Using AV allows you to figure out how aperture works and still produce decent images. Unlike film you can crack off 300 shots and delete the lot at no expense, other than your time and frustration.

How to Use Aperture Priority Mode

Step 1. Switch to Aperture Priority Mode – different cameras have different buttons for aperture priority mode, but it should say something like A or Av.

On the Canon 7D Mkii, you just need to depress the lock button and turn the mode dial until it clicks onto AV.

Step 2. Choose Between Manual or Automatic ISO – at this point just select auto ISO, it’s just one less thing to worry about. If it’s not very bright outdoors, or if you’re shooting indoors, you might want to use manual ISO and set it so that you get a decent speed. To check this just set your ISO and then half press the shutter button. Check your speed setting on the top display or through the view finder. In the image below we can see that the camera is using auto white balance, ISO 800, 1/100 sec, f/1.8, on AI Servo.

What is Aperture Priority in Photography

Whether you are using aperture priority or shutter priority, ISO can help you compensate for a fast shutter speed or a small aperture. If your ISO is set too high it can introduce a lot of noise into your images as the sensor hunts for light. This is perfectly highlighted in the pine marten image. You can see the noise in the black part of the image. I can remove this in Lightroom but it takes time and skill and is very time consuming if you have hundreds of images. If you are interested in learning how to edit using Lightroom them my Editing with Lightroom workshop might just fit the bill.

pine marten

If you have some extra time on your hands, select an ISO manually and see what difference each level makes to your images.

Step 3. Change the Value of Your Aperture

Aperture priority mode makes it very easy to change your aperture setting. On the Canon 7D Mkii, all you need to do is rotate the knurled wheel which sits directly above the shutter button. As I mentioned previously your camera will change the shutter speed as you change your aperture value. Of course it will also change the shutter speed when the light changes.

Step 4. Shoot away

You don’t need to overthink this step. Just choose a subject and take a few test photos. When I was learning I just set the ISO to 400, set up some objects to shoot, (chess pieces if I remember), then took a load of shots using different aperture values. NOTE: I didn’t alter the distance of the camera from the subject. This is important as it will change your focal plane.

I started out with a relatively large aperture, and kept on going until my camera told me it didn’t have enough light. At this point I selected auto ISO. Remember guys there are no rules. You will figure out your ‘photographic style’ as you progress. This image sort of sums me up. Have a go at guessing the settings for this dandelion seed head. Pop your answer into the comment box.

What is Aperture Priority in Photography - dandelion seed head

Conclusion

Understanding what is Aperture Priority in Photography is one of the first real steps to getting creative with your camera.

Using aperture priority mode can definitely help you take control over the creative side of your photography, thereby producing better photos without too much stress. This mode is perfect for beginners, macro, wildlife, portrait, and landscape photographers. It’s ideal for you if you want to achieve a fixed depth of field without worrying about shutter speeds all the time.

Get Off Auto