Light-field photography (also known as plenoptic photography) is an imaging technology that makes it possible to adjust the focus in an existing picture. Unlike conventional images, any area in an image taken with a light-field camera can be brought into focus to make a particular feature sharper or make details of a particular area more visible.
In photography, focus works similarly to how it works in the human eye: When you focus on one part of a scene, that part is clear but everything else is slightly blurred. In conventional photography, image focus is selected before the picture is taken and that focus is fixed in the resulting image. In light-field photography, all the information required to focus on any part of a scene is recorded and stored with the digital image. Clicking on a given area in an image taken with a light-field camera is like looking directly at objects in a scene in front of you: The area you click on becomes clearer while other areas in the scene are less distinct; if you click on a different point, the new area becomes clear while the area you were focused on before it blurs.
Click on different areas in the image to refocus.
The totality of light (photons) traveling within a given scene, through any point in space and in any direction, is known as the light field. Light field photography captures and records information about the light field as it interacts with physical objects in a scene. Leonardo da Vinci explained the concept behind light-field photography back in the fifteenth century. In his manuscripts on painting, Leonardo wrote about the existence of complete information at any point where light can be seen to travel from a given perspective. He described these points of light as “radiant pyramids” interweaving throughout the air without interfering with each other and said that “the semblance of a body is carried by them as a whole into all parts of the air, and each smallest part receives into itself the image that has been caused.” The basic idea is that the light arriving at any point within a scene has all the information required to recreate any view available from that perspective.