Until recently, light field imaging has been performed with systems including several large cameras and a supercomputer. Yesterday, Lytro presented a first consumer level light field camera which will certainly shake the whole camera industry.
Pictures taken with conventional cameras are two dimensional light intensity maps. Light field pictures include also information of the directions of the light rays which can be used in several ways:
- The focus of an image can be set to any distance or the whole image could be made sharp.
- One can measure the distance of the objects in an image that enables 3D modeling.
- Objects in any given distance from the camera could be cropped out easily.
Light field imaging will change the way we use cameras and digital images. The development of this technology is early in it’s life cycle and it will take some time until it will replace conventional cameras. One major area that needs to be improved is the resolution.
During the past decade, the number one selling point of digital cameras has been the number of pixels in the image sensor. Lytro says that their camera can capture 11 megarays. It most probably means that they have 11 mega pixel sensor in their camera. What it doesn’t mean is that the images will have 11 mega pixel resolution.
Light field cameras include a lens array and the number of those lenses determine more or less the end image resolution. Behind each lens in the lens array there is some amount of pixels which are used for determining the direction of the light rays. For example, with 11 mega pixel image sensor and with 25 pixels reserved for each lens in the lens array the picture resolution would be 0.44 megapixels only.
In this manner to have a HD resolution picture with a light field camera one would need to have approximately 92 megapixel sensor (720 x 1280 x 4 x 25 = 92.16M). Have you seen one for sale? I haven’t.
For sensor manufacturers light field imaging means that the pixel race is not over and it will become even more important when light field imaging starts to get more consumer attention.
Scaling down pixels in conventional CCD and CMOS image sensor technologies means that the performance is severely compromised due to cross talk, dynamic range and other issues. Totally new image sensor technologies are therefore required to utilize the full potential of light field imaging.
It looks like there will be interesting times ahead for us enthusiastic photographers.