As discussed there, the mode that gives you ultimate control over shutter speed is Shutter Priority, or S, mode, where you are responsible for selecting the shutter speed while handing over the aperture selection to the camera. The ability to concentrate on just one exposure factor helps you quickly make changes on the fly while staying glued to your viewfinder and your subject.
There are a couple of things to consider when using Shutter Priority mode, both of which have to do with the amount of light that is available when shooting. While you have control over which shutter speed you select in Shutter Priority mode, the range of shutter speeds that is available to you depends largely on how well your subject is lit.
Typically, when shooting fast-paced action, you will be working with very fast shutter speeds. This means that your lens will probably be set to a large aperture. If the light is not sufficient for the shutter speed selected, you will need to do one of two things: Select a lens that offers a larger working aperture, or raise the ISO of the camera.
Zoom in to be sure
When reviewing your shots on the LCD, don’t be fooled by the display. The smaller your image is, the sharper it will look. To ensure that you are getting sharp, blur-free images, make sure that you zoom in on your LCD display.
To zoom in on your images, press the Playback button located below the mode dial on the left and then press the Zoom In button to zoom (Figure 5.4). Continue pressing the Zoom In button to increase the zoom ratio.
To zoom back out, simply press the Zoom Out button (the magnifying glass with the minus sign on it) or press the Playback button again.
Working off the assumption that you have only one lens available, let’s concentrate on balancing your exposure using the ISO.
Let’s say that you are shooting a baseball game at night, and you want to get some great action shots. You set your camera to Shutter Priority mode and, after testing out some shutter speeds, determine that you need to shoot at 1/500 of a second to freeze the action on the field. When you place the viewfinder to your eye and press the shutter button halfway, you notice that the f-stop has been replaced by the word “Lo.” This is your camera’s way of telling you that the lens has now reached its maximum aperture and you are going to be underexposed if you shoot your pictures at the currently selected shutter speed. You could slow your shutter speed down until the Lo indicator goes away, but then you would get images with too much motion blur.
The alternative is to raise your ISO to a level that is fast enough for a proper exposure. The key here is to always use the lowest ISO that you can get away with. That might mean ISO 100 in bright sunny conditions or ISO 3200 for an indoor or night situation (Figure 5.5).
Just remember that the higher the ISO, the greater the amount of noise in your image. This is the reason that you see professional sports photographers using those mammoth lenses perched atop a monopod: They could use a smaller lens, but to get those very large apertures they need a huge piece of glass on the front of the lens.
The larger the glass on the front of the lens, the more light it gathers, and the larger the aperture for shooting. For the working pro, the large aperture translates into low ISO (and thus low noise), fast shutter speeds, and razor-sharp action.
Adjusting your ISO on the fly
- Look at the exposure values (the shutter speed and aperture settings) in the lower portion of your viewfinder.
- If the word “Lo” appears where the aperture normally is, then it’s time to increase the ISO (A).
- Select the higher ISO by observing the control panel while pressing and holding the ISO button on the back of the camera and rotating the Command dial to the right. Once the desired ISO is selected, simply release the ISO button (B).
- If you now see an aperture setting in the display, shoot away. If you still see the word “Lo,” repeat steps 2 through 4 until it is set correctly.