How Does a Light Field Camera Work? – Instant Egghead #13


A good picture is like a time capsule. It lets you capture a moment and enjoy it for many years to come. Modern features like auto-focus
and large image sensors make taking a perfect photo a snap. After the fact we can use software to make images sharper or get rid of things
we don’t want in our photo. But there’s still one thing even
the best digital cameras can’t do: fix a photo that’s out of focus. Remember that blurry mess that was supposed
to capture a kid’s game-winning catch? Fortunately, there’s a camera that can help
even the most photo-challenged of us. A light-field camera lets you fix the focus
of an image even after its been taken. So how does it work? The image sensor in a normal digital camera
adds up all of the rays of light around whatever you’re photographing
and counts them as a single amount of light. It’s helpful to use music as an analogy. Taking a conventional digital photo
is like recording all of the instruments in a band all at once. A light field camera, on the other hand would be like recording individual instruments
on separate audio tracks. That’s because a light field camera uses
a special sensor to record the color and intensity
of light traveling in every direction through every point in space. Breaking down a song into individual tracks
lets you fine tune a sound. In the same way, breaking down a photo
into individual rays of light lets you improve the clarity of a picture
even after its been taken. Lets use a LYTRO light field camera
as an example of how this works. A LYTRO camera has a lens,
a light field sensor, and a micro processor. This set-up isn’t too different
from a normal digital camera. What is different about the LYTRO is
that its sensor is covered by a matrix of micro lenses. These provide an enormous
amount of information about direction, color
and intensity of light. Then, the LYTRO’s micro processor
figures out what an image should look like when it’s in focus. In fact, it doesn’t even have
a focus mechanism. You just point, and shoot. For Scientific American’s
Instant Egghead, I’m Larry Greenemeier.

7 Replies to “How Does a Light Field Camera Work? – Instant Egghead #13”

  1. These cameras sound interesting, but I imagine there is so sort of catch. Do they take longer to "snap" a picture? Or are the images so data intensive that they fill the largest memory cards in just a few shots? I guess I'll have to Google them to learn more…

  2. There's a review on The Verge and Engadget for the Lytro. Do a google search to find these articles.

    Basically, the camera is a cool little gadget, but it's not ready for prime-time photography. However, the technology is exciting.

  3. In 1981-2, we used Scientific American articles in an English course for electronics engineers I was teaching in Neuchâtel (CH): the students understood the topics, I knew the language, so together, we could understand the articles.
    One of those was about fixing out-of-focus pictures taken by satellites – was it already the same a) kind of "sterophonic" digital photo; b) method for fixing a blurred result, as described here?

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