When cameras went from analog to digital, it was one of those once-in-a-generation shifts. But whether you're using a 35-millimeter or a point-and-shoot, the steps you take to shoot a picture have remained the same: you focus on something, then push a button to record the image. 
But what if you could refocus it after you had taken it? What if, just by clicking around a photo on your computer screen, you could choose which part of the image should be clear and which part should be blurry?

    You can with a new camera called Lytro.

    The Lytro can do this because its image sensor captures more data than a standard camera does. Not only does its sensor register how bright the incoming light was and what colors it contained, it also knows which direction the light came from. With that so-called light-field data, the Lytro's onboard software can create multiple focal points.

    The camera is the size and shape of a stick of butter. It's an unconventional design, with a lens at one end and a small, iPod-Nano-size touch screen at the other. It weighs 215 grams, a bit more than some point-and-shoots, but not so much that you would notice. The camera comes with either eight gigabytes of memory (350 pictures, costing $399) or 16 gigabytes (750 pictures, costing $499).

    Like a point-and-shoot, turning on the Lytro is nearly instantaneous; the touch screen comes to life in about a second. But that 3.7-centimeter touch screen is one of the Lytro's weaker points. It's too grainy and small.

    The touch screen's interface is more successful. When shooting, swiping up reveals an onscreen panel with battery life and memory-capacity information. Swiping to the right takes you to previously shot images. You can also switch between "everyday mode," where the refocus range is determined automatically, and "creative mode," which gives the photographer control over the refocus range.

    After a picture has been taken, you can play with focal points on the camera's display, but it's better to do it on a Mac computer. The company says the Lytro will be compatible with Windows-run machines later this year.

    Taking pictures with the Lytro reveals other benefits besides focusing after the fact. Because the camera is pulling in multiple focal points all at once, the Lytro doesn't have the shutter lag that point-and-shoots have. My own test measured the Lytro at one shot about every 1.3 seconds.

    You can upload photos to your computer via the included USB cable. Given that a Lytro picture is meant to be tinkered with, the format is not really intended for printed photos. You can generate a print, but it will be at a fairly low resolution, 1080 by 1080 pixels. That's good enough only for a small print.

    The Lytro has some other drawbacks. For starters, although there is a dormant Wi-Fi chip inside ( so clearly there's going to be some wireless capability) for now you can't share photos on the go.

    And adding a filter or importing the image into Photoshop remains impossible. Then there's the price. Four or five hundred dollars is too expensive for basic photo purposes, and professional users will want more control over settings and lenses.

    But should Lytro's engineers refine light-field photography into something more versatile and cheaper, it may turn out to be a game changer.

    The New York Times