This is the Lytro, a bizarre and radical new concept in digital photography that lets you snap an image now, and worry about focusing it later.

Pre-orders just opened today, and you can grab one for as little as $399 (I’ll take two!). But before you click the order button, make sure you have a Mac – because Lytro doesn’t work with Windows computers yet.

How does the Lytro work? The official description sounds like something from the Hitch Hikers Guide to the Galaxy:

The light field fully defines how a scene appears. It is the amount of light traveling in every direction through every point in space. Conventional cameras cannot record the light field.

But the Lytro can, right? It sounds like it must be the Infinite Improbability Drive of digital cameras, capturing everything everywhere all at the same time. There’s a full explanation of the science behind it on the Lytro site but quite frankly, having read it twice I still don’t really understand what’s going on.

What I do know is that the image files you get from this thing aren’t going to easily import into iPhoto. They’re described as “living pictures”, not your humble jpg file. They require extra software to edit and view them.

And that’s where we find out, tucked away in the details page, that the software supplied with the Lytro is Mac-only for the time being:

Includes a free desktop application for importing, processing and interacting with living pictures from the camera. It is built for Mac OS and requires Mac OS X 10.6 or higher. A Windows application is in development.

Hands up who remembers the days when it was the other way round? When new stuff got released for Windows first, because duh, everyone used Windows – and for Mac much, much later. If at all.

How times have changed.