The Canon EOS Digital Rebel XS/1000D Companion

Chapter 7. Advanced Exposure

LEARNING MORE ABOUT THE XS LIGHT METER AND EXPOSURE CONTROLS

There's more to exposure than what we've seen so far. In addition to motion and depth of field control, exposure control also lets you control tonality in your image. Your exposure control is very dependent on your light meter, though, so to really understand exposure, you have to learn about some of the workings of the XS's light meter. In this chapter, we'll go deeper into metering and exposure and explore some of the XS's image-processing options.

The Light Meter Revisited

In Chapter 1, we looked at the XS's light meter, which analyzes the light in your scene to determine an exposure that will yield an image that's neither too light nor too dark.

The light meter is activated every time you half-press the shutter button, and while the automatic metering in the XS is very good, it can be confused and won't always calculate the best exposure for every scene. For example, consider this image:

Figure 7-1. This image suffers from bad backlighting, which is leaving the subject's face in shadow.

We've looked at a bad backlighting problem before. Because of the bright background, the camera is biasing its metering toward the brighter portion of the image, and the resulting exposure leaves the person underexposed. ...