The Nikon D90 Companion

Chapter 7. Advanced Exposure

LEARNING MORE ABOUT THE D90 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 D90’s light meter. In this chapter, you’ll go deeper into metering and exposure and explore some of the D90’s image-processing options.

The Light Meter Revisited

In Chapter 1, you looked at the D90’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 although the automatic metering in the D90 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.

You’ve seen a bad backlighting problem before in this book. Because of the bright background, the camera is biasing its metering toward the brighter portion of the image, and the resulting exposure leaves ...