Every Image Possible

Focus on the Face?

Or focus on the blade?

Look at any image captured by a traditional camera.  What you are seeing is a two dimensional representation of the scene captured from one angle. What if your camera could capture every possible image from the scene?  How would that change photography? At SIGGRAPH last month, Kurt Akeley, CTO of Lytro, explained how this happens in his company's light field camera system.

This image from Lytro shows the path of the light field.

The light field is a mathematical function that describes the amount of light faring in every direction through every point in space. Light travels in rays and the primary measurement of a ray of light is radiance. The Lytro camera captures radiance values in a scene in a way that allows the computation of the entire light field in front of the lens. This allows the user to adjust the point of focus and other image parameters after the image is captured.

This diagram from the Lytro web site shows the inside of the camera.

Lytro achieves the light field capture by using an 8x optical zoom lens to focus the scene on a micro-lens array adhered to a standard digital image sensor. The micro lenses allow each area of the sensor to capture the image from one view with a total capture of 11 million rays. From these rays, a two dimensional or three dimensional representation can be computed for any view and these can be recalculated based upon input from the viewer.

Lytro calls the images from their system "Living Pictures" because the viewer can adjust the point of focus on their own computer.  Their camera system was released in February of this year and the Living Picutres must be viewed in special Lytro software for your PC or Mac or in a special Lytro plugin on a website.

The ability to change the focal point of an image after it is captured has profound implications on the very definition of photography. Is the photographer the person who captures the image, or the person who determines the focus parameters after capture?

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The images at the top were captured with a Lytro Light Field camera at Comicon 2012.