I’m fascinated by the concept, partly because it answers a question I’ve always had. There’s so much visual data in the average photo that’s indecipherable, whether due to parts being out of focus, shot in poor light, and so forth. A bad pic is like a badly damaged hard drive, with only some of the “files” readable. Can’t technology figure out a way to recover the unrecoverable data?

Yep, it can.

Lytro’s founder and chief executive is Ren Ng, 31. His achievement, experts say, has been to take research projects of recent years — requiring perhaps 100 digital cameras lashed to a supercomputer — and squeeze that technology into a camera headed for the consumer market later this year.

Mr. Ng explained the concept in 2006 in his Ph.D. thesis at Stanford University, which won the worldwide competition for the best doctoral dissertation in computer science that year from the Association for Computing Machinery. Since then Mr. Ng has been trying to translate the idea into a product that can be brought to market — and building a team of people to do it.

The Lytro camera captures far more light data, from many angles, than is possible with a conventional camera. It accomplishes that with a special sensor called a microlens array, which puts the equivalent of many lenses into a small space. “That is the heart of the breakthrough,” said Pat Hanrahan, a Stanford professor, who was Mr. Ng’s thesis adviser but is not involved in Lytro.

Focusing after the fact isn’t the only breakthrough:

The technology works in very low light without a flash, Lytro said, while 3-D glasses can add a particularly vivid effect—simulated three-dimensional images that users can adjust to show different perspectives.

Conventional digital cameras essentially record the total sum of light rays from a scene as they hit an image sensor, Mr. Ng said. A light-field camera records the color, intensity and direction of rays individually. He compared the approach to audio recording; instead of recording multiple musicians all at once, modern multitrack studios record them separately so that the volume and other effects can be independently adjusted after the fact to create a sound mix.

Here’s the “how it works” page on Lytro’s website. If you want to experiment with the technology, try their one-click photo gallery. Just one question: As neat as this is, who’s going to shell out several hundred bucks for a standalone flex-focus camera? I remember dropping $500 in 2002 on a Canon Powershot with 4 megapixel resolution. Fast-forward nine years and I get a better image than that from my iPhone, with plenty of zoom features, filters, etc, available via apps in the iTunes store. Unless I’m a semi-serious photographer, why would I spend extra money on a separate camera that I have to lug around? And if I am a semi-serious photographer, why would I “cheat” by using after-the-fact focus instead of challenging myself to take the perfect shot in real time? There will be a market for this camera, I’m just … not sure who it’ll be.

They’ve got two obvious business strategies going forward, I think, and neither relies on semi-serious photogs. One: Miniaturize the technology to the point where it’s cell-phone ready and then sell it to Apple or Google or whoever. Having a feature like this in the iPhone to let you sharpen up shoddy pics would be lovely. Two: Surveillance. Isn’t that the most obvious application for this? How many times have you watched a true-crime show where the perp walks by a gas-station camera 25 feet away and the best they can do to get a description of him is magnify his face until it’s a pixelated blotch? Universal focus would be a very tasty treat for security agencies. There’s certainly a market for it. Chop chop, Lytro!