Rob’s recent post over at Boing Boing drew my attention to computer scientist Ren Ng’s startup, Lytro, which is developing a digital camera technology that requires no moving parts to focus an image at any depth of field, even infinite. It’s called “light field” photography, and, besides eliminating failure-prone moving parts from cameras, it will let you refocus your pictures however you want, as many times as you want, any time after they’ve been captured. I don’t claim to completely understand the process, but here are what seem like the important facts:

1. Instead of one big lens, “light field” cameras have lots of little “micro-lenses”—one for each pixel.
2. Besides pixel color and intensity (which are recorded by conventional cameras) “light field” cameras also capture the direction of the incoming light for each pixel.
3. Knowing the vector path of the light that makes each pixel allows for a sort of “reverse ray-tracing” routine that can virtually refocus the image at the software level.

Fascinating stuff. There’s more info at The Economist, and at Lytro, including an interactive photo gallery that shows off the refocusing trick.