Capturing the Screen

Let's say you want to write a book about the iPhone. (Hey, it could happen.) How on earth are you supposed to illustrate that book? How can you take pictures of what's on the screen?

For the first year of the iPhone's existence, that challenge was nearly insurmountable. People set up cameras on tripods to photograph the screen, or wrote hacky little programs that snapped the screen image directly to a JPEG file. Within Apple's walls, when illustrating iPhone manuals and marketing materials, they used a sneaky-button press that neatly captured the screen image and added it directly to the Camera Roll of pictures already on the iPhone. But that function was never offered to the public—at least not until the iPhone 2.0 software came along.

Now it's available to everyone. The trick is very simple: Start by getting the screen just the way you want it, even if that means holding your finger down on an onscreen button or keyboard key. Now hold down the Home button, and while it's down, press the Sleep/Wake switch at the top of the phone. (Yes, you may need to invite some friends over to help you execute this multiple-finger move.)

That's all there is to it. The screen flashes white. Now, if you go to the Photos program and open up the Camera Roll, you'll see a crisp, colorful, 480 x 320-pixel JPEG image of whatever was on the screen. At this point, you can send it by email (to illustrate a request for help, for example, or send a screen from Maps to a friend who's driving ...

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