oreilly.comSafari Books Online.Conferences.


AddThis Social Bookmark Button

Screenshot Hacks for Mac OS X

by Wei-Meng Lee and Derrick Story

Capturing great screenshots in Mac OS X involves a little adventure. If you simply want to capture something on your monitor for reference later on, you can do that easily with the built-in screen capture tool. However, if you are a professional writer (or a student preparing an important report) and need great-looking screenshots, you have to spend a little more time exploring your options.

What if you want to capture moving pictures from your screen, such as a QuickTime video clip or a scene from a DVD movie, as well? With a little ingenuity, you can elevate your screen-capture prowess to grab just about anything that appears on your monitor, moving or not. Here are a few tips how.

Built-in Screenshot Capabilities: The Basics

Mac OS X comes with built-in capability for capturing screen shots. To capture the entire screen, you can simply press Command-Shift-3.

To capture a region of the screen, press Command-Shift-4, then click and drag the cursor to mark the area you want to capture. When you lift your finger from the mouse button, Mac OS X will record that real estate and place a .pdf file on your desktop.

Screen shot.
Figure 1. Capturing a portion of the screen.

While the built-in screen capture tool is good enough for most purposes, it has the following drawbacks:

  • The mouse pointer will not be captured. Figure 2 shows the capture of a pull-down menu without the cursor.

    Screen shot.
    Figure 2. The mouse pointer will not be captured using the built-in screen capture tool.

  • In Jaguar, images can only be saved in .pdf format. This is an inconvenience for people who need to save their images in other formats, including .jpg, .png, or .gif.

Using Grab for More Functionality

Mac OS X also ships with the Grab utility, located in the Applications -> Utilities folder. To use Grab, double-click on its icon and choose the type of image you want to capture.

Screen shot.
Figure 3. Using Grab for screen capture.

Grab supports three modes of screen capture:

  • Selection: Select the region you want to capture using the mouse
  • Screen: Capture the entire screen
  • Timed Screen: Capture the entire screen after a specific time interval

Surprisingly, the fourth mode, Window capture, is not functional in Jaguar.

Unlike the built-in screen capture utility, Grab allows mouse pointers to be captured. You can capture actions like clicking on a menu item by using the Timed Screen mode, as shown in Figure 4.

Screen shot.
Figure 4. Using the Timed Screen mode to capture actions.

There is one problem that I noticed with Selection mode. In order to capture an active window using Selection mode, you need to switch to Grab first. Doing so makes the window inactive. Now, when I do a Selection grab, I would want to capture the window in the active state. To make the window active, you can right-click on the window and perform your capture. This technique will not work all the time. In particular, I have problems in capturing the System Preferences window using this technique.

Screen shot.
Figure 5. Unable to save the active System Preferences window.

The selection grab will also display the size of the image you are capturing at the bottom right corner of the selection region. This is useful if you need to capture images of an exact size. One gripe I have, though, is over Grab's inability to reposition the selection region.

Unlike the built-in screen capture utility in Mac OS X Jaguar, Grab saves the images in .tiff format.

Mac OS X Hacks

Related Reading

Mac OS X Hacks
100 Industrial-Strength Tips & Tricks
By Rael Dornfest, Kevin Hemenway

One cool feature in Grab is the option to include different mouse pointers (or simply hide the mouse pointer) in the screen capture. To activate this feature, click on Grab -> Preferences. A window containing all of the different mouse pointers will be shown, as in Figure 6.

Screen shot.
Figure 6. Grab allows you to capture mouse pointers.

Screen shot.
Figure 7. Capturing the mouse pointer with Grab.

Saving a Large Document that Spans Many Screens

What if you want to save a big document, such as a long HTML page, that spans many screens on your monitor? An easy method, that's built right into Mac OS X, is to convert it the page to a .pdf file.

Go to the File menu and then choose Print. At the bottom of the Print dialogue box, you will see a button that reads Preview. Click it and it will process your document and open the Preview application that's included with Mac OS X.

You'll notice that when your document is displayed in the Preview application (or sometimes in Adobe Acrobat), it already looks like a .pdf file. Now all you have to do is choose File, then Save As PDF, and Mac OS X will convert your entire document into a real live multi-page .pdf document.

This is much easier than using Grab to save multiple screens, and then have to keep them in the proper order.

Pages: 1, 2, 3

Next Pagearrow