iPhoto® ’09 For Dummies®

Chapter 9. Using the Histogram for Advanced Editing

In This Chapter

• Identifying the histogram

• Reading a histogram

• Using a histogram to create an editing plan

Before you can arrive at your destination, you must know where you're going. To effectively use the power of advanced editing techniques, you need to understand how to determine what corrections need to be made to bring out the best in your photos.

A histogram is a great tool that doesn't just tell you what's wrong with a photo — it shows you. A histogram also makes clear what the application of any corrections will do to your photograph. This is key to taking advantage of the power of iPhoto's advanced editing capabilities.

In this chapter, I introduce you to histograms and how to understand what they mean for your photographs, current and future. Learning to interpret histograms helps you correct current photo problems, such as exposure and lighting, and avoid the same photographic problem areas in the future.

Tip

Any descriptions of the interplay of light, sensors, and electronics can easily become unnecessarily complex, so I'm going to try and avoid doing that. This means that although the descriptions I give are correct, they might not be complete. For your purposes, though, they'll be enough.

Defining a Histogram

Regardless of the photo format you choose for your camera's output (if you'd like to know more about photo formats, see ...