Do you find that the screen of your MacBook, MacBook Air, or even a 15-inch MacBook Pro looks uncomfortably small after using a 21-inch or 27-inch iMac? If so, and you’ve also got an iPad, iPhone, or iPod touch, spend a few bucks on a dandy app called Duet Display and you can increase your screen real estate.
The app — well, actually, it’s two apps: one for your Mac and one for your iOS device — allows you to use your iDevice as an extra display. I use Duet Display to set up my iPad Pro as a secondary display for my 12-inch MacBook when I’m traveling. It works seamlessly.
Developed by a team of ex-Apple engineers, Duet Display delivers a retina display at 60 frames per second with zero lag. Before Duet Display, I used an app called Air Display that also allowed you to use your iOS device as a second display. However, it used Wi-Fi for connectivity, so there was noticeable screen lag on my iPad. Duet Display uses a physical connection.
When you begin setting up the apps, it’s easy to see that ex-Apple engineers did the work. You need two software applications to make duet work. First, install duet for iOS. The latest version is 1.0.0 and requires iOS 7.0 or later.
After installation, you'll see the icon on your iDevice’s home screen. Tap on it to open when you want to use duet.
Next, you need duet for Mac. The latest version can be downloaded from duetdisplay.com/mac (it’s free) and requires OS X 10.9 or later. To install, double click the app.
The app will move to Applications and ask for your permission to add a graphics driver. The driver is required to render the high performance display on your iPad. The installation will only add an additional driver for Duet's operation and won’t affect your current system drivers.
Once the driver and app is installed, restart your Mac. After rebooting, you should see duet's icon, a circle with a lowercase d, running in the menu bar. You can access duet settings by clicking on this icon and then the settings gear inside the status window.
Start duet on your Mac and on iOS and connect your iPad or iPhone to your Mac using a 30-pin or Lightning cable. When duet detects the iPad or iPhone it will change the message from Connect to Mac to Launching Duet right before your new desktop is displayed on the Mac.
The software — which works in either portrait or landscape mode — offers energy saving options for folks using older Macs that aren't as powerful as the latest models. You can choose between regular and Retina resolution, as well as switch between a 30Hz and 60Hz refresh rate.
Duet Display is available at the Mac App Store for $7.99 (that’s 50% off the regular price). It requires OS X 10.9 on a Mac. The iOS version is free and available at the Apple App Store. It requires iOS 8.0 or higher on an iPad, iPhone, or iPod touch.