mordant wit

A prototype camera made by a Stanford University graduate student could herald the end of fuzzy, poorly lit photos.

A computer science Ph.D. student at Stanford University has outfitted a 16-megapixel camera with a bevy of micro lenses that allows users to take photos and later refocus them on a computer using software he wrote.

The student, Ren Ng, ran out of patience with taking pictures the traditional way -- adjusting the distance between the camera lens and sensor or film before snapping each shot. So he created something that far surpasses Photoshop. A photograph can be modified after the fact even if nothing is in focus, he said.

'We just think it'll lead to better cameras that make it easier to take pictures that are in focus and look good,' said Ng's adviser, Stanford computer science professor Pat Hanrahan.

Ng calls his creation the 'light field camera' because of its ability to capture the quantity of light moving in all directions in an open space. It stems from early-20th-century work on integral photography, which experimented with using lens arrays in front of film, and an early-1990s plenoptic camera developed at MIT and used for range finding. By building upon these ideas, Ng hopes to improve commercial cameras' focusing abilities.

Traditionally, light rays filter through a camera's lens and converge at one point on film or a digital sensor, then the camera summarizes incoming light without capturing much information about where it came from. Ng's camera pits about 90,000 micro lenses between the main lens and sensor. The mini lenses measure all the rays of incoming light and their directions of origin. The software later adds up the rays, according to how the picture is being refocused.

The technology could help snap-happy amateurs and professional photographers, as well as aid security cameras in capturing sharper information.

Turning Ng's invention into a commercial product poses a few challenges. First, it works best with expensive high-resolution cameras, and when you add the price of Ng's device, the cost could be prohibitive (Ng declined to estimate a cost). A photographer could get pretty good results by modifying an 8-megapixel camera with Ng's invention, but it wouldn't be possible to refocus over as wide a range.

On the other hand, the invention could make cameras simpler in some ways. A camera equipped with Ng's device wouldn't need the motors that focus lenses, so the camera would have fewer moving parts.