Section 8.10. The Adjust Panel

8.10. The Adjust Panel

For thousands of people, the handful of basic image- fixer tools described on the previous pages offered plenty of power. But many others wound up disappointed with previous iPhoto versions.

Power users were irked at having to trot off to some other program like Photoshop to make more advanced changes to their pictures, like fiddling with the saturation (the intensity of colors) or the sharpness of the image. Meanwhile, Apple clearly detected that the landscape of inexpensive photo editors was changing; even the most basic free digital shoebox program for Windows offered full-blown image controls.

All of which sets the stage for one of iPhoto 5's most important new features: the Adjust panel (Figure 8-6). It appears whenever you click the Adjust button in editing mode.

Note: Except for the Brightness and Contrast controls, the Adjust palette doesn't work unless your Mac has at least a G4 processor. And if you want to apply these effects to photos in the RAW format, you'll need Mac OS X 10.3.6 or later.

Now, before you launch yourself into the following pages and turn yourself into a tweak geek, here are some preliminary words of advice concerning the Adjust panel:

  • When to use it . Plenty of photos need no help at all. They look fantastic right out of the camera. And plenty of others are ready for prime time after only a single click on the Enhance button, as described earlier.

    The beauty of the Adjust panel, though, is that it permits infinite gradations of the changes that the Enhance button makes. For example, if a photo looks too dark and murky, you can bring details out of the shadows without blowing out the highlights. If the snow in a skiing shot looks too bluish, you can de-blue it. If the colors don't pop quite enough in the prize-winning soccer goal shot, you can boost their saturation levels.

    In short, there are fixes the Adjust panel can make that no one-click magic button can touch.

  • How to play . You can fiddle with an Adjust panel slider in any of three ways, as illustrated in Figure 8-6.

  • Backing out . You can always apply the Undo and Revert to Original commands to work you perform with the Adjust panel. But the panel also has its own Reset Sliders button, which essentially means, "undo all the Adjust-panel changes I've made during this session."

    Tip: The Reset Sliders button is also useful when you just want to play around with an image. You can make some adjustments, see how they look, then hit Reset Sliders before closing the window or clicking the Done button. In this case, iPhoto leaves the photo just as it was.
  • Moving on . The Adjust panel is a see-through, floating entity that lives in a plane of its own. You can drag it anywhere on the screen, andhere's the part that might not occur to youyou can move on to a different photo without having to close the panel first. (Click another photo among the thumbnails at the top of the screen, for example, or click the big Previous and Next arrows at the bottom.)

8.11. Introduction to the Histogram

Learning to use the Adjust panel effectively involves learning about its histogram , the colorful little graph at the bottom of the panel.

The histogram is the heart of the Adjust palette. It's a self-updating visual representation of the dark and light tones that make up your photograph. If you've never encountered a histogram before, this all may sound a little complicated. But the Adjust palette's histogram is a terrific tool, and it'll make more sense the more you work with it.

Within each of the superimposed graphs (red, blue, green), the scheme is the same: The amount of the photo's darker shades appears toward the left side of the graph; the lighter tones are graphed on the right side.

Therefore, in a very dark photographa coal mine at midnight, sayyou'll see big mountain peaks at the left side of the graph, trailing off to nothing toward the right. A shot of a brilliantly sunny snowscape, on the other hand, will show lots of information on the right, and probably very little on the left.

Figure 8-6. You can drag the handle of a slider, of course, but that doesn't give you much accuracy. Sometimes you may prefer to click directly on the slider, which makes the handle jump to the spot. Finally, you can click repeatedly on the ending icons to move the handle in very fine increments .

The best-balanced pictures have some data spread across the entire histogram, with a few mountain-shaped peaks here and there. Those peaks and valleys represent the really dark spots (like the background of a flash photo) and bright spots (a closeup face in that flash picture). Those mountains are fine, as long as you have some visual information in other parts of the histogram, too.

The histogram for a bad photo, on the other handa severely under- or overexposed onehas mountains all bunched at one end or the other. Rescuing those pictures involves spreading the mountains across the entire spectrum, which is what the Adjust palette is all about.

8.11.1. Three Channels

As noted on the previous page, the histogram actually displays three superimposed graphs at once. These layersred, green, and bluerepresent the three "channels" of a color photo.

When you make adjustments to a photo's brightness valuesfor example, when you drag the Exposure slider just above the histogramyou'll see the graphs in all three channels move in unison . Despite changing shape, they essentially stick together. Later, when you make color adjustments using, say, the Temperature slider, you'll see those individual channels move in different directions.