The Lytro does so using Light Field technology, in which the camera captures the intensity, color, and direction of every light ray in the image. (A conventional camera captures the sum of all light rays in the image, instead of each individual.) Because of the massive amounts of data taken in for each image, it is possible to revisit the image later, either on a computer or on the camera's display, and change the focus of the image.
The technology is perhaps better explained in an analogy used by the creators of the camera:
"Compare pictures taken with Light Field to recording a studio session with a one-track recorder versus a multi-track recorder. Traditional digital cameras are like capturing all the instruments in musical piece on a single audio track. The Lytro is like giving each instrument its own track and the photographer the power to blend those tracks creatively." - Tech News WorldIn the past, Light Field technology required multiple cameras attached to a computer, but is now available in the tiny 1.6 x 1.6 x 4.1 inch Lytro, described as looking like an over-sized tube of lipstick.
The camera itself is a novelty, described by one reviewer as a "bona fide technological breakthrough," but it could also have a considerable effect on the creative process of photography. Giving a photographer the ability to focus an image after shooting it would cut back on the number of decisions and adjustments that need to be made while shooting. This could have a number of implications in the creative process. Will it make photography less creative and less spontaneous, or will it offer more creative possibilities in editing? Or, will it simply reassign where in the process of photography one can be creative?
Right now, the Lytro camera is seen by most photographers as a gimmick or toy: rudimentary, impractical and expensive. However, they also seem to agree that it's worth keeping an eye on in the future. Photographer David D. Busch sums it up perfectly:
"Controlling the depth of field and focus is one of the most important creative tools that a photographer has" and "the ability to do that later, if they can get that perfected, can be very important in the future."
"Right now, it's not practical, but you could have said the same thing about digital SLRs in the early 1990s...but they grew into the technology we have today that's taken over and put Kodak out of business."