The Magic Behind iPhoto For iPad’s Beaming



One of iPhoto for iOS’s most useful new sharing features is called Beaming. It lets you send your photos quickly and directly to anyone sharing your Wi-Fi network and also running iPhoto.

As good, long-time Mac users we remember the bad old days of networking, where getting two Macs to talk to each other was all but impossible, and hear-tearingly frustrating at best (even when they were joined to opposite ends of the same Ethernet cable). Clearly, something has changed. So just how does iPhoto Beaming work?

TUAW’s resident nerd and developer Erica Sadun explains all. Beaming is a custom transfer scheme built for iPhoto, although it’s similar in approach to the way iOS connects gamers together for multi-player games.

Using Bonjour (formerly Rendezvous), iDevices advertise themselves on the local network (just like AiPlay devices). Then, when you decide to beam a photo, your copy of iPhoto looks around for friendly faces. If it finds one, they talk to each other and negotiate a connection. Photos then transfer over the network.

This is pretty cool, and avoids all the usual pains of network setup. Erica has a more technical lowdown on the protocols used and so on in her article. But it’s not quite as cool as the way AirDrop works on your Mac.

AirDrop does two things. It uses a Bluetooth-like protocol to find other Macs that are broadcasting their presence, and then hooks up an ad-hoc Wi-Fi network between them. This is why AirDrop only works on newer Mac hardware — it needs the right wireless chipsets to enable the direct connection, while still not knocking you off your existing connection.

The neatest part of AirDrop is that it works for machines that don’t share a network. It would work in a desert, as the machines talk directly to each other.

If you use AirDrop at home, it’s pretty pointless, but out and about it can be very cool indeed.