S mode is what we photographers commonly refer to as Shutter Priority mode. Just as the name implies, it is the mode that prioritizes or places major emphasis on the shutter speed above all other camera settings (Figure 4.6).
Just as with Program mode, Shutter Priority mode gives us more freedom to control certain aspects of our photography. In this case, we are talking about shutter speed. The selected shutter speed determines just how long you expose your camera’s sensor to light. The longer it remains open, the more time your sensor has to gather light.
The shutter speed also, to a large degree, determines how sharp your photographs are. Even though an image may appear sharply in focus, any movement by the subject or the camera while the shutter is open can blur the image. If you think about it, when you are trying to show motion, you want a slower shutter speed because it blurs the image.
A good rule of thumb for avoiding blurry images is to always use a shutter speed as fast as your focal length. For instance, if I’m out photographing my daughter with an 80mm lens, then I’ll want to make sure my shutter speed is at least 1/120 of a second, taking into account that the camera is not full frame, so the actual focal length is greater than the focal length of the lens. Anything less than that might cause camera shake (even if you’re equipped with biceps as big as Popeye’s). The D7000 has a 1.5x magnification, so if your focal length is 100mm, you shouldn’t shoot less than 1/150 of a second.
A slow shutter speed refers to leaving the shutter open for a long period of time—like 1/30 of a second or less. A fast shutter speed means that the shutter is open for a very short period of time—like 1/250 of a second or more. The faster the shutter, the less information your sensor can gather, so you will get less detail in your image.
When to use Shutter Priority (S) mode
- When working with fast-moving subjects where you want to freeze the action (Figure 4.7);
- When you want to emphasize movement in your subject with motion blur (Figure 4.8)
- When you want to use a long exposure to gather light over a long period of time (Figure 4.9);
- When you want to create that smooth-looking water in a waterfall (Figure 4.10)
As you can see, the subject of your photo usually determines whether or not you will use Shutter Priority mode. It is important that you be able to previsualize the result of using a particular shutter speed. The great thing about shooting with digital cameras is that you get instant feedback by viewing your shot on the LCD screen. But what if your subject won’t give you a do-over? Such is often the case when shooting sporting events. It’s not like you can go ask your daughter to score another goal in her soccer game because your photograph was blurry from a slow shutter speed. This is why it’s important to know what those speeds represent in terms of their capabilities to stop the action and deliver a blur-free shot.
First, let’s examine just how much control you have over the shutter speeds. The D7000 has a shutter speed range from 1/8000 of a second all the way down to 30 seconds. With that much latitude, you should have enough control to capture almost any subject. The other thing to think about is that Shutter Priority mode is considered a semiautomatic mode. This means that you are taking control over one aspect of the total exposure while the camera handles the other. In this instance, you are controlling the shutter speed and the camera is controlling the aperture. This is important, because there will be times that you want to use a particular shutter speed but your lens won’t be able to accommodate your request.
For example, you might encounter this problem when shooting in low-light situations: If you are shooting a fast-moving subject that will blur at a shutter speed slower than 1/125 of a second but your lens’s largest aperture is f/3.5, you might find your aperture display in your viewfinder and the rear LCD panel will display the word “Lo.” This is your warning that there won’t be enough light available for the shot—due to the limitations of the lens—so your picture will be underexposed.
Another case where you might run into this situation is when you are shooting moving water. To get that look of smooth, flowing water, it’s usually necessary to use a shutter speed of at least 1/15 of a second. If your waterfall is in full sunlight, you may get a message that reads “Hi” because the lens you are using only stops down to f/22 at its smallest opening. In this instance, your camera is warning you that you will be overexposing your image. There are workarounds for these problems, which we will discuss later, but it is important to know that there can be limitations when using Shutter Priority mode.
Setting up and shooting in Shutter Priority mode
- Turn your camera on and then turn the Mode dial to align the S with the indicator line.
- Select your ISO by pressing and holding the ISO button on the back left of the camera while rotating the main Command dial with your thumb.
- The ISO will appear on the top display. Choose your desired ISO, and release the ISO button on the left to lock in the change.
- Point the camera at your subject and then activate the camera meter by depressing the shutter button halfway.
- View the exposure information in the bottom area of the viewfinder or by looking at the rear LCD panel.
- While the meter is activated, use your thumb to roll the Command dial left and right to see the changed exposure values. Roll the dial to the right for faster shutter speeds and to the left for slower speeds.