The other day I was in a conversation in which somebody wondered whether camera chips would keep increasing in resolution. After all, when you can already take a picture with 20 million pixels, why bother to go higher?
At which point it occurred to me that an affordable sensor element with 100 million pixels, or even more, would be very useful. Not for taking pictures of higher resolution, but for changing the nature of cameras in a more fundamental way. If I had a sensor with a vast number of pixels, I would put an array of little lenses over it. with each lens having just a modest number of sensor elements behind it (say, a million or two).
There are two important things about this scenario: The first is that each little lens is in a slightly different position. Those slight positional differences allow the camera to capture an entire lightfield. Once you have a lightfield, you can reconstruct the 3D shapes of things, or selectively kick various objects out of focus in software, or all sorts of other cool things you can’t do with a conventional camera. This is essentially the magic sauce behind the Stanford spinoff company Lytro.
But the other cool thing about this scenario (and Lytro hasn’t figured this out yet, but they will soon, or else somebody else will), is that you can make a camera that’s totally flat, like a credit card. Because those tiny little lenses don’t need the long focal length of a big lens — they only need to be a small fraction of an inch in front of the sensor element. Just take that flat credit card out of your wallet, hold it up, and you can start capturing rich lightfields.
This is both good news and bad news. The good news is that a whole new class of extremely cheap cameras which can capture reality far better than today’s cameras will be everywhere — on clothing, wallpaper, floor tiles, stick-on decals — anywhere there is a surface.
The bad news? Well, reread that previous paragraph and think about the implications. The good news is the bad news.