Having that slick 9.7-inch iPad sitting idle while you’re hammering away at your MacBook seems like a bit of a waste, and so Air Display promises to turn the tablet into a secondary display. Avatron’s app uses a WiFi connection to bridge MacBook to iPad wirelessly; we checked the $9.99 software out.
Installation is straightforward, with instructions popping up on-screen the first time you run Air Display on the iPad. Basically, you need to download the roughly 2MB OS X installer – currently there’s no Windows version, though Avatron say it’s in the works – and run that; after a restart you have a new icon in your OS X toolbar from which you can access the Air Display preferences and choose an iPad to extend the display to.
The choice of preferences themselves are minimal, frankly. You can turn Air Display on or off, pick an iPad to connect to and choose whether or not the app checks for updates automatically and sits its icon in the toolbar. Display settings are handled through OS X’s normal preferences, and from there you can drag the iPad around depending on whether it’s to the left or right (or above, or below) your existing display(s). Both machines must be on the same network, and you can set your MacBook up as an ad-hoc wireless point if that’s not possible.
Pick your iPad from the list and both screens flash blue briefly; after that you can drag windows off the main screen and onto the iPad’s display as you would with any normal multi-display setup. Both portrait and landscape orientations are supported, with another blue flash after each rotation. If you exit the iPad app and then restart it, you’ll need to re-select the iPad from the MacBook, since there’s no automatic-reconnect option.
Image quality is always going to be the deciding factor with an app like Air Display, and the obvious limitation is the WiFi network itself. Avatron say they use “a clever dynamic compression algorithm” to improve responsiveness, which basically adds up to reduced quality for moving graphics. The first time you drag something onto the iPad display there are noticeable artefacts and pixelation; after a few seconds, assuming it stays motionless, the resolution tightens up and looks basically the same as it would on your MacBook display.
Unsurprisingly that means video is not the app’s friend, dropping frames left, right and center and generally stuttering through clips. It’s not entirely unwatchable, if you’re desperate to see some particular footage, but for any serious viewing you’ll want to return to the main display. There’s no way to manually control the amount of compression Air Display uses, either, so you’re at the mercy of its “dynamic” algorithm.
Air Display maps touches of the iPad’s screen to mouse clicks, which means you can interact – in some ways – with programs without reaching for the actual mouse or trackpad. This works best with apps that have large, finger-friendly buttons, but less so with webpages. There’s no finger-scrolling support as you’d find in Mobile Safari, for instance, so you’ll need to carefully tap and drag the actual scroll bar. There’s also no easy way to flick windows between the two (or more displays); we’d like to see a “send to iPad” button that would automatically move a window to the iPad’s screen and maximise it.
If you’re looking for a way to offset Photoshop toolbars, music controls, IM windows and Twitter apps from your main screen then Air Display works well. Video and anything with dynamic graphics – like games – are less successful, though, and we’d still opt for a regular, wired monitor. Still, considering USB secondary displays like those from Nanovision are upward of $120 for less screen real-estate and similarly mediocre video performance, if you’ve already got an iPad then the ten bucks for Air Display seems a bargain.
Air Display is available through iTunes now, priced at $9.99.
