In January 2006 I wrote an article about some cool things you can do on your Macintosh computer. One of the things I discussed was screen capture in Mac OS-X, and in many comments, both on Digg and my website, I’ve noticed that number of people didn’t quite understand its full potential. Some Windows users’ comments go along the lines of ‘In Windows you just press “Print Screen” on the keyboard, how’s that for a cool feature?’ or even ‘Print screen is all you need for a screen capture in Windows.”

Let’s think about this for a moment. Firstly, the key label ‘Print screen’ itself is wrong. One thing you would expect from it is to, well – print the screen. You press it and the content of the screen gets printed on your printer. But no, all you get is screen content copied into the clipboard. For the new computer users pressing it usually leads to “What the…” situation. At least on Windows, I’m not so sure about Linux.

But we can give it a credit for being there for a couple of decades and most of Windows users know what it’s for. After all, we all know that when we pay cargo, it’ll go by the ship, and when we pay shipment it will go by the car.

So what does the PrintScreen really do in Windows. You press it and it copies your desktop screen into the clipboard. If you hold down the Alt key while pressing PrintScreen, it will copy only active window into the clipboard. And that’s it. If you want to keep that ‘screenie’ you need to open another application, paste it there and then save it. What application comes to mind? MS Paint, umhhhhh… Even worse, people often paste it into Word Document, making it 5 MB file that could have gone in 300KB.

If you want to capture only the part of the screen (e.g. orange part below) you need to print… capture the screen with ‘PrintScreen’, then paste it into MS Paint, cut it in pieces there and save as jpeg file. So, without extra work and additional application PrintScreen does exactly nothing.

Mac screen capture

Now let’s see how we can do this on Mac. You press Cmd-Shift-4 and you get crosshair pointer. To select region just click and drag, then let go. The captured area will be stored as Picture 1.png on your desktop. No need for any editing as you captured exactly what you wanted.

If you need to keep this file, well, there it is, keep it. Just move it to a location of your choice. If you want to use it in another document just drag it into that document, and if you still need to edit it for some reason, just double click on it and it’ll open in Preview, ready to be cut again.

If you don’t need the file, you just want to paste it straight into an email or a document, you can press Ctrl-Cmd-Shift-4 and select capture area in the same way. Then simply paste it into your document. And, unlike Windows’ .bmp file, this one is .png, so no issues with 5MB emails here.

ical captureWhen capturing the whole window, you don’t need to select it in order to capture it. What does that mean?

Let’s say I’m typing this article and need a screen shot of a window that is actually behind the active one and is only partially visible, in this case iCal.

All I need to do is to press Cmd-Shift-4, hit space bar to get camera-poiner, hover over the portion of the iCal window that is still visible and click. The iCal screen shot .png file will be saved on my desktop and nothing will change the focus, I just continue typing. Now imagine usability of this when working with two dozen open windows in PhotoShop.

So what Mac OS X does with screen capturing is far beyond reach of “PrintScreen”. I din’t have a chance to check if Windows Vista addresses this, but I wouldn’t be surprised if it didn’t.