Sometimes screenshots can be hard to get – for example if the usual keyboard shortcut for taking a screenshot (Command + Shift + 3) performs some other actions in the program you are trying to capture, it might not work properly.
This is where timed screenshots prove to be very useful. Apple has designed nifty little application, called Grab, which helps you out in these situations.
Here is how it works:
You can access Grab easily by opening Finder -> Applications -> Utilities. Once the app is running, click on “Capture” in the menu bar and select “Timed Screen” (or you can press Command + Shift + Z)
Now click on the “Start Timer” button and stage your screenshot. You will have 10 seconds before Grab takes a screenshot. Of course, the application itself won’t be visible on the screenshot.