Autofocus cameras hit the stores back in the 1970s, making it dramatically simpler for the average consumer to get a good shot. Later the digital camera made it possible for just about anyone to process their own pictures at home on a computer. Now comes a camera that could represent another kind of photography revolution: the light field camera. Take the picture, but focus it afterwards. Robert Siegel speaks with Lytro founder Ren Ng about the new light field camera that his company is producing.