This is the camera we told you about earlier, a camera that produces photos whose focus may be changed after the picture has been taken. Itâ€™s variously called a plenoptic camera, 4D light field camera or Digital Lens (which seems to be the preferred commercial name). It was perfected by Stanford PhD graduate Ren Ng, based on the work done by MIT researchers John Wang and Edward Adelson in 1992. He presented it Wednesday at a San Francisco meeting of the Camera Owners of the Bay Area or COBA.
The new prototype uses a 16-megapixel Contax 645 camera with added multiple microlenses in between the photo sensor and the main lens, thus turning a standard camera into a light field camera. According to a paper written by Ren Ng and other researchers at Stanford, the added microlens array measures light distribution on each ray of light, which is information that is normally lost on traditional cameras. By collecting that vital information through custom post-production software, the Stanford researchers were able to compute sharpness at different focal lengths.
A different pixel could then be extracted from the microlens image to change the point of view of the observer across the aperture plane, that is, altering the focal length of the â€œsynthetic image,â€ the paper added.
Ren Ng has organized Refocus Imaging, Inc. to commercialize his work.