Over the last nine posts, we’ve talked a lot about the importance of learning to work with the individual exposure settings if you want to take creative control of your images.
Now it’s time to put the rubber to the road! It’s time to put all this new knowledge of exposure into practice.
First it’s important to understand that the only way you are going to be able to take control of exposure is if you get out of the ‘Auto’ mode on your digital camera. In Auto mode, your camera makes all of the exposure decisions for you. But your camera can’t know the look you want for your photo. It can’t know that you want to separate your subject from the background by using a shallow depth of field. It can’t know that you want to capture an image that freezes the motion of a quivering leaf.
The result is that the images taken while on Auto are more often than not unremarkable. You may occasionally snap a great photo, but it’s hit or miss, the luck of the draw.
In other words, shooting on Auto is holding you back.
For this reason, I strongly urge you to get away from using your camera’s Auto exposure setting. But that doesn’t necessarily mean that you have to dive into fully manual mode. Luckily, there are other mode options–the Priority Modes–that let you take control the look of your photos while still making use of your camera’s exposure meter and taking advantage of its ability to calculate exposure.
The Priority Modes
The Priority modes–Aperture and Shutter Priority–are semi-automatic modes. In these modes, you set two of the exposure controls. The camera then chooses the third control, selecting a setting so that the image is properly exposed.
In a sense, the priority modes gives you the best of both worlds. You have control over the exposure setting that matters for the image you want to capture, but you are still able to rely on the camera’s automatic functions to ensure that your image is correctly exposed.
Let’s look at each of the Priority modes separately.
Aperture Priority Mode
Aperture Priority mode, labeled either A or Av on your camera’s mode dial, lets you set both the aperture size and the ISO. The camera then selects a shutter that works with these settings so that your image is correctly exposed.
Since the aperture size affects the depth of field in an image, Aperture Priority is a good choice when the amount of focus is important in your image.
So using Aperture Priority is a good idea when you want a shallow depth of field to set your subject apart from the background…
…Or when you want everything in the scene crisp and in focus.
To see this all in action, check out the two videos below, both by Mike Browne of Picture This (Imaging) Ltd..
Shutter Priority Mode
Shutter Priority mode, labeled either S or Tv on your camera’s mode dial, lets you set both the shutter speed and the ISO. The camera then selects an aperture setting that balances these settings out so your photo is properly exposed.
We’ve already talked about how the shutter speed affects the way that speed is shown in an image. For that reason, Shutter Priority is a good choice any time motion–whether it’s in your scene or with your camera–is an issue.
So you will want to use Shutter Priority if you have a concern about camera shake. And Shutter Priority is a good option when you want to freeze motion in your scene:
Shutter Priority can also help you capture the blur of motion in a scene.
And, again, Mike Browne has done a video that will help you understand the use of the Shutter Priority mode.