In This Chapter
The four elements of exposure
Sensitivity: the role of ISO
Intensity: the role of the aperture
What is depth of field?
Time: the role of shutter speed
Putting it all together
Maybe you purchased the Digital Rebel XTi/400D to gain more creative flexibility than is offered by other cameras. And maybe you're still stuck in the Basic Zone exposure modes, but you're anxious to move into the Creative Zone modes to take advantage of the camera's creative options. This chapter offers you a good start in understanding basic photographic concepts—concepts that are the foundation for making the most of the creative potential that the camera offers.
If you've used a film SLR, this chapter may be a refresher for you. If you haven't used an SLR, this chapter will help you build a foundation from which you can expand your skills. Either way, you can learn quickly with the Digital RebelXTi/400D because you can see the results immediately. Instant feedback from the camera lets you determine whether you're on target or you need to make adjustments.
Whether you use the Basic or the Creative Zone modes, you can get better pictures with the Digital Rebel XTi/400D when you understand the basics of exposure. As you read this chapter, don't worry about remembering everything at once. Take your time and enjoy the process of learning.
Think of exposure as a precise combination of four elements—all of which are related to ...