Aperture Priority Mode is represented by an “A” on your Nikon camera or “Av” on your Canon camera.
Aperture priority mode is a semi-manual mode where you set the aperture value and the camera sets the shutter speed for you.
So for example, if you want to shoot at aperture f/4.0, the camera will keep shooting at f/4.0 unless you change it. The shutter speed will be set by the camera. (If your ISO is set on Auto ISO, the ISO will be set by the camera as well).
WHY SHOOT IN APERTURE PRIORITY MODE?
Here are few reasons why you’d want to shoot in Aperture Priority Mode:
1. Creative Control over Depth of Field
On previous posts, we’ve looked at ISO, Aperture and Shutter Speed and how they relate to each other in getting well exposed images. If you remember, one of the things aperture controls is the Depth of Field(DOF).
Wide apertures like f/1.8, f/2.0, or f/2.8 gives you shallow depth of field. The area that is in focus is small, leaving the rest of the scene to be blurry and out of focus. This is good for isolating the subject from the background. It makes the subject stand out.
In the above scenario, you’re making wide aperture a priority, because you want shallow depth of field. So by using Aperture Priority mode, you’re able to lock in at a wide aperture such as f/2.0, so that every shot you take are taken at f/2.0 giving you a shallow DOF.
If you’re shooting landscape, you’d want large depth of field to make more of the scene in focus and sharp. Small apertures such as f/16 or f/22 are used to achieve this.
In this scenario, you’re making small aperture a priority, because you want large depth of field to keep your scene in focus and sharp. By using Aperture Priority mode, you can lock in the aperture at f/16 by example, so that every shot you take are taken at f/16.
The photos below shows how Depth of Field changes according to what aperture you use.
2. Low light situations
When shooting in low light situations without a flash, you’d want a wide aperture to let in as much light as possible. This depends on the lens you have, so you’d be at an advantage if your lens is has a wide apertures like f/1.2, f/1.4, f/1.8 or f/2.0. This is one of the reasons why I recommend the affordable 50mm f1.8 and the 35mm f/1.8 or f/2.0.
In this scenario, you need to make wide aperture a priority, because you want to bring in as much light as possible to the camera. So by using Aperture Priority mode, you can lock in the aperture at f/1.8 for example, so that you’re letting the most light in with every shot you take.
3. Inconsistent lighting situations
There are going to be times when you’d be taking pictures and the lighting condition keeps changing. The clouds in the sky may be passing, causing the sun to peek in and out, or whoever you’re photographing maybe constantly moving from shade to sun. That is a difficult situation to be photographing in manual mode since you’d have to constantly change settings on your camera as the lighting condition changes. Automatic mode can help you in these situations but if you want your photos at a constant aperture value, then aperture priority mode is the answer.
In this scenario, you’d make aperture a priority, because creatively you want a consistent look of shallow depth of field. The camera will set the shutter speed for you and give you a correct exposure.
HOW TO SHOOT IN APERTURE PRIORITY MODE
Is this all making sense?
Here are simple steps on how to shoot in aperture priority mode:
1. Turn the dial to A(Nikon cameras) or Av(Canon cameras)
2. Set your ISO. (This is always one of the first things you should do. In plenty of daylight: Keep your ISO low at 100 or 200, In low light indoors: Keep your ISO high at 800 or 1600)
3. Dial your aperture value to according to your need or taste.
4. Shoot, shoot and shoot!
*Shoot in different aperture values and compare the results.
**Another thing. If you shoot enough you may eventually notice, in some situations your image might be too bright or too dark. You can adjust your exposure level with exposure compensation. It’s another control settings in your camera. What? You might as well shoot in manual mode, right? We’ll take a look at exposure compensation in an upcoming post.