You might occasionally need to capture the image on your computer screen so you can save or share it. If you've used a PC designed to run Microsoft Windows, you've probably used the Print Screen key on the keyboard to do this. If you're using a Mac, though, you'll notice Apple doesn't include such a key. Don't worry, though, because we're about to look at the keyboard combinations and built-in tools you can use on your Mac to capture what you need from the screen.
First, let's look at the keyboard combinations you can use to capture the image on your screen. The keystrokes for screenshots are multiple keys that should be pressed together. When you do this, press and hold the first key, then the second, and so forth, and immediately release all keys after pressing the final one in the sequence. The following are the keystrokes to remember for screen capturing:
Command+Shift+3 captures the entire screen and saves it to a file on your desktop.
Command+Shift+4 temporarily replaces your mouse cursor with a tool to select any rectangular portion of the screen. Click and drag the tool to make your selection. Your cursor immediately returns to normal after that selection.
Control added to the start of either of these sequences saves the image to the clipboard temporarily instead of to a permanent file. That allows you to copy and paste what you see on the screen into an application, such as image editing software.
If you don't use the Control key, your Mac saves these keystroke captures to your desktop by default. When you're capturing images this way, you won't see any system or app notifications to verify success. Instead, the system just plays a chime that sounds like a film camera snapping a photo. To see the files you're saving, you'll have to either open your Finder or minimize your windows to find the images saved on the desktop.
Mac OS X traditionally saved keyboard-generated screenshots as tagged image file format (TIFF) files. Macs switched to portable document format (PDF) starting in the 10.2 release of OS X, and to portable network graphics (PNG) files by 10.6. Later, we'll look at how you can convert any of these images to other file formats.
While keystrokes let you get a quick capture from the screen, they have limited options for what you're capturing. That's where the Grab utility comes in. Next, let's take a look at how to use Grab, including how to capture a specific window and how to time the capture to include things like mouse-over text or drop-down menus.