14.10. Screen-Capture Keystrokes
If you're reading a chapter about printing and graphics, you may someday be interested in
creating screenshots—printable illustrations of the Mac screen.
Screenshots are a staple of articles, tutorials, and books about the Mac (including this
one). Mac OS X has a secret built-in feature that lets you make them—and includes some
very cool convenience features.
Here's how to capture various regions of the screen.
14.10.1. The Whole Screen
Press Shift- -3 to create a picture file on your desktop, in PNG format, that depicts the
entire screen image. A satisfying camera-shutter sound tells you that you were successful.
The file is called Picture 1.png. Each time you press Shift- -3, you get another file,
called Picture 2, Picture 3, and so on. You can open these files into Preview or any other
graphics program, in readiness for editing, printing, or exporting in a different format.
Tip: It doesn't have to be Shift- -3. You can change this keystroke, or any of these
screenshot keystrokes, to anything you like. Open System Preferences Keyboard &
Mouse Keyboard Shortcuts. Expand the Screen Shots list. Click the keystroke you
want to change, and then press the new key combo you prefer.
14.10.2. One Section of the Screen
You can capture just a rectangular region of the screen by pressing Shift- -4. Your
cursor turns into a crosshair with two tiny digital readouts—the horizontal and vertical
coordinates of your cursor on the screen at this moment. (The numbers are pixels, as
measured from the upper-left corner of the screen, which has coordinates 0, 0.)
Now drag diagonally across the screen to capture only a rectangular chunk of it. When
you drag and release the mouse, you hear the camera-click sound, and the Picture 1 file
appears on your desktop as usual—containing only the rectangle that you enclosed.
In Leopard, in fact, this feature has been goosed up quite a bit. Once you've begun
dragging diagonally, while the mouse is still down, you can press any of these keys for
special manipulation effects:
• Space bar. While you hold down the Space bar with one hand, your selection
rectangle is frozen in size and shape. With your mouse hand, you can move the
cursor with the entire selection rectangle attached, the better to fine-tune your
positioning relative to your target.
• Shift key. When you hit Shift, you confine the dragging action of your mouse to a
single dimension: horizontal or vertical. Which dimension depends on how you
move your mouse after you hit Shift.
For example, suppose you drag out a two-inch square, and then you pause. With
the mouse button still down, you press Shift. If you now continue to drag
downward, the selected area maintains a fixed width; you're increasing only the
• Option key. If you hold down Option after beginning to drag, Mac OS X creates a
rectangular selection that grows from the center point outward. That is, it treats
your initial click as the rectangle's center point, rather than as a diagonal corner.
14.10.3. A Dialog Box, Menu, Window, or Icon
Why fuss with cleaning up a screenshot after you've taken it? Using this trick, you can
neatly snip one screen element out from its background.
Make sure the dialog box, menu, window, or icon is visible. Then press Shift- -4. But
instead of dragging diagonally, tap the Space bar.
Your cursor turns into a tiny camera (Figure 14-15). Move it so the misty blue
highlighting fills the window or menu you want to capture—and then click. The resulting
Picture file snips the window or menu neatly from its background.
Figure 14-15. To capture just one dialog box, use the old Camera Cursor trick. That
is, invoke Shift- -4 and then tap the Space bar to produce the cursor shown here.
Click the element you want to snip it from its background. (Press the Space bar a
second time to exit "snip one screen element" mode and return to "drag across an
area" mode.) If you ever change your mind about taking any kind of screenshot,
press -period or the Esc key.
Shift- -4 and then the Space bar also captures the Dock in one quick snip. Once
you've got the camera cursor, just click any blank spot in the Dock (between icons).
Tip: If you hold down the Control key as you click or drag (using any of the techniques
described above), you copy the screenshot to your clipboard, ready for pasting, rather
than saving it as a new graphics file on your desktop.
As noted in Chapter 10, Mac OS X also offers another way to create screenshots: the
Grab program in your Applications Utilities folder. Grab's chief selling point is its
timer option, which lets you set up the screen before it takes the shot.
But if you're really serious about capturing screenshots, you should opt instead for Snapz
Pro X (www.ambrosiasw.com), which can capture virtually anything on the screen—
even movies of onscreen procedures, along with your narration—and save it in your
choice of graphics format.