The light field…is a function that describes the amount of light travelling through every point in 3D space in every possible direction.
This prototype camera records this light field over time. Using “a microlens array between the sensor and main lens” the amount of light arriving along each ray is recorded. This data enables the destination of the rays to be computed later, which in turn means that the image can be re-focussed at the editing stage.
It seems to work very well. See the site for example pictures and movies – the swimming video is remarkable. The resolution of the prototype is 300 x 300, but they’re working on a 1MP version. It’s a Stanford project currently and nowhere near to any kind of mass production, but this would be a massive innovation if it’s scalable. Modern CCDs can already capture two or three stops of data in their RAW formats, allowing some exposure manipulation later, and coupled with this a photographer need only worry about shutter speed and composition at the time of taking the shot. Very cool indeed.