Canon® EOS 5D Digital Field Guide

Chapter 5. Working with Canon EX Speedlites

In This Chapter

• Exploring E-TTL technology

• Choosing a Canon EX-series Speedlite

• Using Speedlites

• A compendium of flash techniques

Countless scenes offer great opportunities for using one or more accessory Canon EX-series Speedlites, whether the scene is backlit or the subject and background are lit at different levels. And while using a flash is great for standard photography, it also offers creative opportunities for capturing everything from a drip of water to stroboscopic motion.

This chapter details choosing and using accessory Canon EX-series Speedlites. While it is not an exhaustive look at all the ways you can use Speedlites, it provides an overview of the technology, as well as some techniques that you can use with one or more Speedlites and the EOS 5D.

Exploring E-TTL Technology

The latest Canon's EX-series Speedlites employ E-TTL II technology. E-TTL stands for Evaluative Through-The-Lens flash exposure control. In simple terms, E-TTL II technology receives information from the camera, including the focal length of the lens, distance from the subject, exposure settings including aperture, and the camera's built-in evaluative metering system to balance subject exposure with the ambient light.

Note

While E-TTL II works with all lenses, not all Canon lenses communicate distance information that is used in the algorithm that calculates flash exposure. Generally, lenses with a ring-type Ultrasonic Motor (USM) return distance information. Lenses ...