Canon EOS Rebel T8i/850D For Dummies. Julie Adair King

of inactivity to save battery power. To wake the camera up, press the shutter button halfway and release it. See the information related to the Auto Power Off setting, found in the section “Setup Menu 2,” later in this chapter, for help adjusting the timing of the automatic shutoff.

       Mode dial: Rotate this dial to select an exposure mode, which determines whether the camera operates in fully automatic, semi-automatic, or manual exposure mode when you take still pictures. Chapter 2 introduces you to the various exposure modes.

       Viewfinder adjustment dial: Use this dial to adjust the viewfinder focus to your eyesight, as outlined in the preceding section.

       Main dial: As its name implies, this dial is central to many camera functions, from scrolling through menus to changing certain shooting and playback settings.FIGURE 1-6: Here’s a guide to controls found on top of the camera. On some menu screens, you see a symbol that resembles the top half of a dial with notches around the edge, as shown in Figure 1-7. That symbol indicates that you use the Main dial to adjust the setting. On some screens curved arrows appear near the Main dial symbol. In Figure 1-7, you see one arrow under the Main dial symbol and another on the left side of the screen. When using the touchscreen, you can tap those arrows to adjust the setting instead of using the Main dial.FIGURE 1-7: The notched half-circle symbol tells you to use the Main dial to adjust the setting.

        AF Method/AF Area Selection button: Press this button to access the AF Method and AF Area Selection settings, both related to autofocusing. Chapter 5 explains.

       ISO button: True to its name, this button displays a screen where you can adjust the ISO setting, which determines how sensitive the camera is to light. Chapter 4 details this critical setting.

       DISP button: This button affects the Quick Control screen, which displays shooting information when you’re taking still pictures. (Check out “Displaying the Quick Control screen,” later in this chapter, for a look.) Normally, the screen appears automatically when you turn the camera on or press the shutter button halfway and release it; the screen then turns off after a period of inactivity. But you can press the DISP button at any time to toggle the screen on and off.

       Shutter button: You no doubt already understand the function of this button, but you may not realize that when you use autofocus and autoexposure, you need to use a two-stage process when taking a picture: Press the shutter button halfway, pause to let the camera set focus and exposure, and then press down the rest of the way to capture the image. You’d be surprised how many people mess up their pictures because they press that button with one quick jab, denying the camera the time it needs to set focus and exposure.

       Flash hot shoe: Labeled in Figure 1-6, this is the connection for attaching an external flash and other accessories such as flash adapters and the Canon GP-E2 GPS Receiver.

        Focal plane indicator: Should you need to know the exact distance between your subject and the camera, the focal plane indicator, labeled in Figure 1-6, is key. This mark indicates the plane at which light coming through the lens is focused onto the camera’s image sensor. Basing your measurement on this mark produces a more accurate camera-to-subject distance than using the end of the lens or some other point on the camera body as your reference point. You might take advantage of this feature when taking pictures for a legal or scientific purpose that requires you to submit the camera-to-subject distance along with the photos.

       Speaker: When you play a movie that contains audio, the sound comes wafting through these holes.

       Microphone: You can record movie audio via the built-in microphone, which picks up sound from the two holes labeled “Microphone” in Figure 1-6.

      Back-of-the-body controls

Traveling over the top of the camera to its back, you encounter the smorgasbord of controls shown in Figure 1-8.

      FIGURE 1-8: Having lots of external buttons makes accessing the camera’s functions easier.

Some buttons have multiple “official” names because they serve multiple purposes depending on whether you’re taking pictures, reviewing images, recording a movie, or performing some other function. In most cases, this book refers to these buttons by the first label you see in the following list (and in Figure 1-8) to simplify things. Again, though, the margin icons and figures show you exactly which button to press to accomplish the task being discussed.

Here’s an introduction to the controls on this side of the camera:

        AF Point Selection/Magnify button: In certain shooting modes, you press this button to specify which autofocus points or zones you want the camera to use when establishing focus. You can also press and hold the button during Live View or Movie shooting to magnify the display to check focus. (Chapter 5 tells you about focusing features.) In Playback mode, covered in Chapter 9, you press the button to magnify the image display (thus the plus sign in the button’s magnifying glass icon).

        AE Lock/FE Lock/Index/Reduce button: During shooting, you can press this button to lock autoexposure (AE) settings, as covered in Chapter 4, or to lock flash exposure (FE), a feature detailed in Chapter 2.This button also serves two playback functions: It switches the display to Index mode, enabling you to see multiple image thumbnails at once. And if you magnify a photo, pressing the button reduces the magnification level.

        AF ON button: In the camera instruction manual, Canon uses the name AF Start button for this control, which no doubt will stymie many users’ efforts to search the manual for information on the AF ON button. But AF Start actually is applicable in that pressing the button initiates autofocusing, giving you an alternative to pressing the shutter button halfway to get that job done. Experienced photographers refer to this as back-button autofocus because the button usually is located on the back of the camera, as it is on the T8i/850D. There are several situations in which using the AF ON button makes good sense; the autofocus sections of Chapter 5 provide more insight.Two additional points about the AF ON button:The AF ON function works only when the Mode dial is set to P, Tv, Av, or M. In Canon lingo, those four shooting modes are called Creative Zone modes.You can assign a different function to the button if you don’t want to use it for autofocusing. Chapter 11 explains how to modify the function of this and other buttons on your camera.

        Live View/Movie-record button: Press this button to shift to Live View mode, which enables you to compose your pictures using the monitor instead of the viewfinder. When shooting movies, press the button to start and stop recording. (You must first set the On/Off/Movie switch to the Movie position.)

        Q (Quick Control) button: Press this button to shift to Quick Control mode, which enables you to adjust major shooting settings quickly. See