Understanding Aperture Priority Mode

In Photography Tips by max

Once you understand the aperture settings on your camera, you can produce wonderfully blurred backgrounds, with only the main subject of your image in focus, or use it to bring everything into focus from the nearest tree to the furthest hill in the same image.

Aperture is the size of the hole within your lens, and this is what lets light into your camera. The larger the aperture, the more light you let into your camera sensor, and the shallower the depth of field becomes. It can be confusing to go over to fully manual mode on a camera, so one of the easiest ways to start learning about how your aperture can enhance your creativity is to use Aperture Priority (AP) mode. AP mode gives you control over the aperture (f/stops) on your camera, while the camera will adjust the shutter speed and ISO to compensate for the f/stop you choose.

Why Use Aperture Priority Mode?

You may be wondering why you should change from Program or Auto modes, but if you use AP mode, there are several benefits:

• You get to control the depth of field, not your camera. This means you can choose how much background blur you want in your images.
• It allows you to set your aperture for the type of photography you want to do. For landscapes, you would set it between f/8 and f/22 for maximum sharpness, while for portraits you may choose an aperture between f/1.4 and f/5.6 for good background separation.
• When you lower your aperture, you allow more light into the camera, which means your shutter speed will be quicker. This allows you to hand-hold your camera in lower light conditions without getting blurry images.

Finding Aperture Priority Mode on Your Camera

Photo by Focus Camera on Unsplash

On a DSLR, there is a dial on top of the camera with letters around it. It’s probably set by default to Auto or Program mode. Aperture Priority is the mode usually called AP or AV on Canon cameras – AV stands for Aperture Value, which is just another way of saying Aperture Priority. All you do is turn the dial until the AP mode lines up with the marker, and turn your camera on. It’s as simple as that! You will now be able to use your camera dials to move the aperture value up and down. Try it and see how the shutter speed and ISO also change as you change the aperture.

Depth of Field: What it is, and How You Can Use it in AP Mode to Create Impact

Depth of field is basically using your aperture to control how much of the shot is in focus. The size of the aperture has a direct relationship to how much or little of your image appears sharp.
For instance, a large f-stop such as f/22 (which lets less light in than a lower f-stop) will give you an image with all the foreground and background in focus. Most landscape images are shot with a higher f-stop, but not all.

A small f-stop such as f/1.8, on the other hand, will isolate your subject from the background and blur everything that is not on that plane of focus. Think of close-up portraits where only the eyes are sharp, and everything else gradually falls off into softness. Food photography is an area where shallow depth of field is often used to separate food items from the background.

Photo by Yoori Koo on Unsplash

  • Wide Depth of Field
    You can see in the image below how a landscape has been shot with a wide depth of field (large f-stop – small aperture) This allows all of the image to be sharp from front to back.

Photo by Pascal Debrunner on Unsplash

  • Shallow Depth of Field
    This image of a sunflower is a perfect example of shallow depth of field (small f-stop – large aperture)

The flower itself is in perfect focus, but the background behind it is softly and completely blurred. This is how depth of field is used to effectively isolate a subject against a distracting background.

When to Use Aperture Priority Mode

AP mode is best used in good light, so that you won’t need a tripod to steady the camera as the shutter speed will be high enough to stop camera shake from blurring your shots.
On a sunny day, the old rule is to shoot at ‘sunny 16’ – set your aperture to f/16 and it usually works well.

Portraits, whether you’re using natural light or flash, are often best taken with a narrower depth of field to give that background separation. If you’re in good light, set your aperture to f/5.6 or a lower number, and it will give a pleasing blur behind your subject. How much blur also depends on how far away they are from the background – the further away, the more blur you’ll get in the background.

Some people like to shoot portraits at f/8, as it is usually the sharpest spot on most lenses, but you will get a lot of the background in focus at this aperture, unless your subject is far from the background.

Landscapes, as mentioned before, are usually taken with a wider aperture to have a photo that is sharp from front to back. You may need to use a tripod at larger f/stops, as your shutter speed will drop because less light is getting to the sensor.

When Not to Use Aperture Priority Mode

It’s hard to use AP mode accurately in low light situations, as you will likely end up with blurry images. Shutter Priority mode would be the best mode to use for low light, as you can set a shutter speed you can still hand-hold the camera at (for me, that’s only 1/80th second, but other people can get sharp images hand held at lower shutter speeds – it depends how steady your hands are!).
You also wouldn’t use AP mode for shooting anything moving that you wanted to freeze the action of. Again, that’s a job for Shutter Priority mode, where you would set your shutter speed to around 1/250th second to freeze movement.

Aperture Priority Mode is a great way to begin your journey to fully manual mode, and it allows you some creative control over your images. Don’t be afraid to experiment with different apertures to make some dramatic and different effects.