O'Reilly logo

Canon EOS 40D Guide to Digital Photography by David D. Busch

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

Choosing a Metering Method

The 40D has four different schemes for evaluating the light received by its exposure sensors. You can choose among them by pressing the Metering Mode Selection button on the top panel, and using the Main Dial until the icon for the mode you want appears in the status LCD.

  • Evaluative. The 40D slices up the frame into 35 different zones, shown in Figure 4.3 (the status LCD icon is shown in the upper-left corner). The zones used are linked to the autofocus system. The camera evaluates the measurements, giving extra emphasis to the metering zones that indicate sharp focus, to make an educated guess about what kind of picture you’re taking, based on examination of thousands of different real-world photos. For example, if ...

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required