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By Jonathon Keats; Illustrations by by Kris Holland and Gary McLeod

HOW A STANDARD CAMERA WORKS

Standard cameras gather light through a single central lens and project it onto a sensor, making a flat picture with only one focal point per image. Humans, on the other hand, view objects from two perspectives at once (called binocular vision), so we're sensitive not only to the location of light rays but also to their angle. This lets us see the full depth of what's in front of us and choose where to focus.

HOW THE LIGHT-FIELD CAMERA WORKS

1. Take Several Shots at Once
With multiple eyes—Adobe's prototype has 19—the light-field camera is even more perceptive. Each of its lenses is faced with a prism set at a unique angle, so it can take 19 pictures simultaneously, with each capturing a different part of the scene in focus. Each image uses a piece of the sensor, so a 100-megapixel camera will yield 19 5.2-megapixel shots.

2. Fill in the Blanks
But the process doesn't stop there. Adobe software can analyze the 19 captured photos and from them generate thousands of intermediate images so that each shot seamlessly morphs into those adjacent. Then images are layered, like thin sections, producing a three-dimensional simulation of the scene in which every piece of it is in focus.

3. Paint in Your Focus
Because a light-field photograph is dynamic—virtually three-dimensional—focus can be selectively painted in with a "focus brush," allowing the photographer to bring details from both foreground and background into focus—something that's currently impossible in a single photo. Or future online photo sites could let viewers manipulate a photo's focus as they choose.




MEGAPIXELS ARE GETTING CHEAP

Specs are already circulating for a 22-megapixel cellphone camera, and within a few years 300-megapixel sensors will be no problem. But lenses, ground from glass, can’t focus light sharply enough to take advantage of this windfall. In other words, at some point you simply can’t capture any more detail. Engineers at Adobe Systems, pioneers of Photoshop, see this limitation as an opportunity to rethink photography and put those megapixels to work. Their prototype “light field” lens attaches to a normal digital camera to shoot the same image from dozens of focal points at once. Later, software combines all the images, so you can refocus your photos after they’ve been shot. A system from Stanford University researchers achieves a similar effect by placing a lens like this directly over the sensor.




SIZE: 5 in.
NUMBER OF SHOTS IT CAPTURES AT ONCE: 19
AVAILABLE: Adobe built this prototype to demonstrate its software, but commercial versions could arrive in a few years.








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