Lytro is the world first light field camera

Lytro is the world first light field camera. Light field is the amount of light travelling in every direction through every point in space. Light field contains a lot more information than traditional light captured by regular cameras, especially pertaining to the placement of objects emitting that light and their distance from the camera.

Traditional cameras capture light and color but light field cameras also captures vector direction of the rays of light. This extra bit of information, combined with the special light field sensor and the powerful software, lets the camera know the position of the objects in the frame, which is what lets it perform its magic trick, focus selectively on objects AFTER they are captured by the camera.

Normal cameras use a manual or focusing system to focus on one object in the frame or the entire frame, depending upon the size of the aperture. Once its focused and a image is captured it becomes permanent and there is no way to change the focus after that. Lytro, on the other hand, takes a picture with no focusing whatsoever, which also makes it quicker than traditional cameras. After that it uses all the information it captured and with the help of some techno wizardry from the software presents you with an image that can be refocused any number of times, at whichever point you want in the frame.