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Practical Mac

It’s no longer news that we are surrounded by screens. The television used to be the only screen in people’s lives (not counting the mesh variety keeping bugs outside), but now we’re interacting with computer monitors, laptop displays, tablets and smartphones.

For the latter two, the screen effectively is the device. Take away the screen and it’s useless.

But what’s interesting is that all of those screens act independently. We don’t use them together much, even though the ability to do so exists. Gradually, though, we’re making better use of them.

Take Apple’s AirPlay technology to start. The Apple TV is primarily a box that streams content over the Internet or a local network, but AirPlay makes it possible to send content from a Mac or iOS device to an HDTV. If a friend has a movie on his iPad or iPhone that we both want to see, he can come over and stream it to my television via the Apple TV.

As another example, I shot a bunch of photos during a kids’ party and wanted to share them with the other parents while the kids burned off their sugar highs. I imported the pictures into my iPad and then displayed them on the host’s television via his Apple TV.

AirPlay is great for teachers and others who give presentations but don’t want to mess with cables. (I wrote about my wireless setup for delivering a Macworld/iWorld conference session from my iPad; see “Using an iPad simplifies wireless presentations,” Feb. 2).

But there are many other uses for the technology.

For instance, I sometimes need to record what’s happening on my iPad when developing training materials. Again, this is helpful for teachers, but it also applies to people who want to help a remote family member troubleshoot a problem or learn a new task, or even folks who want to record their progress in a video game so they can upload the result to YouTube later.

iOS doesn’t allow you to record what happens on screen (other than static screenshots), but two applications employ AirPlay to let you view the live screen on your Mac (called “mirroring”). Reflector ($12, and AirServer ($14.99, turn your computer into an AirPlay receiver, just as if it were another Apple TV on your network.

Both apps offer settings for controlling the scale of the screens as they appear on the Mac, and both also support having multiple iOS devices connected. AirServer offers more control over how the screen appears, with sliders for sharpness, brightness, contrast, saturation and hue. Reflector includes the capability to record the mirrored screen.

Recent Macs running OS X Mountain Lion can also mirror their screens to an Apple TV. If you have a slightly older model, as I do, you can get the same functionality by using AirParrot ($9.99, In addition to mirroring your entire screen, AirParrot can extend it, using your HDTV as a second display. Or, if you don’t want to share everything on your screen, you can mirror just a single app. AirParrot also works under Windows.

One last way to make the most of numerous screens is Air Display ( In my office I connect my MacBook Pro to an external monitor, but sometimes having two screens isn’t enough. Using Air Display for Mac ($19.99), I can commandeer a third monitor that’s physically connected to a Mac mini. (Air Display communicates over the local network; it doesn’t use AirPlay.)

When I’m traveling and need more screen real estate, I’ll sometimes use the Air Display iOS app ($9.99) to turn my iPad into a second monitor. It is, after all, a brilliant color screen. Air Display can even take advantage of the iPad’s Retina resolution.

Screens continue to proliferate, so I think we’ll see more of this type of interaction between various devices. They won’t need to be separate devices that either spend most of their time sleeping or act independently.

Jeff Carlson writes the Practical Mac column for Personal Technology and about technology in general for The Seattle Times and other publications. Send questions to More Practical Mac columns at