Your camera has a bunch of different modes, probably many more than you would ever care to learn. Each of them is designed to help you out with one or more shooting situations. In this article, we’re going to take a look at aperture priority mode. It’s one of the main shooting modes on most digital SLR cameras, and it offers a handy way to isolate one variable in your photography. Let’s have a look under the hood to see what it does!
You can get to aperture priority mode by twisting your camera’s top dial to the letter “A” or “Av”. At least, that’s for most cameras. If you have a point-and-shoot with an aperture priority mode, it might be different.
Once you’re in aperture priority mode, you can only adjust one variable, and you guessed it. It’s 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. Let’s dig a little deeper.
When your camera’s aperture is more open, it takes in more light. This offers you a huge advantage when it comes to taking pictures indoors or in low light situations. Instead of having to use a flash, you can simply click the shutter and get something more natural looking.
Of course, this benefit doesn’t come without some cost. As your aperture opens, you get less depth of field. In other words, there is more blurring both in front of and behind your subject. This is a good thing for portraits because the background usually isn’t that important (at least not as important as the face), but it can become a problem when you want to take a picture of a landscape. When you look at a landscape, you want to see far and wide, and when there’s any blurring, this simply isn’t possible.
So, how does aperture priority mode work?
Now that you know a little bit about apertures, I can better explain aperture priority mode. 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 a lot like automatic mode, but you get a little bit more control. By controlling the aperture, you control the depth of field, which as we’ve said is 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 off 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. I suggest you play around with aperture priority mode so you can see exactly which aperture and shutter speed combinations it’s coming up with. Watch how, as the aperture’s f-number increases, the shutter speed decreases. Knowing this will give you an edge when you start learning manual photography.
If you need more help, I explain all about Aperture and Depth of Field along with plenty of examples in my Digital Photo Secrets video course.
Disadvantages of aperture priority mode.
Aperture priority mode is an automatic mode, and that means your images will be subject to the many problems that go along with automatic photography. You camera doesn’t always get its light readings correct. It doesn’t always “know” what type of shooting situation you’re in. If you’re pointing your camera at the sun, for example, you might accidentally get an overexposed or underexposed image.
In my experience, aperture priority mode works best when the light is already even or diffuse. That means shoot in aperture priority mode on cloudy days. This is the one situation that is the least likely to confuse your camera’s automatic mode. If you know enough about photography to shoot in manual, I always advise you to do so. It will help you factor in all of the little things that your camera isn’t smart enough to account for.