Light field photography is an interesting concept: Instead of capturing an image created by the main lens on the sensor directly, the image created by the main lens at some point – in front of or behind the sensor – is again focused by an array of micro-lenses of extremely short focal length onto the sensor. The micro-lenses, with their short focal length, have relatively deep depth-of-field, and thus can bring a lot of content from the main lens’ image into focus at once on the sensor. The main lens can then have a very wide aperture (thus allows more light to be captured) and still have a very deep effective DOF, allowing more things to be in focus.
An interesting side-effect is that by analyzing where on the sensor the secondary image is focused onto, the camera can deduce the object’s distance from the camera, creating a “depth map” of the picture, effectively building a 3D model of the scene via a single photo!
Click and drag to change angle; click to refocus
While RayTrix was more well-known in the scientific world for their 3D camera, Lytro was the first to brought this technology to the masses, with cameras and tools geared toward consumers and photographers, complete with a place for people to share and view lightfield photos as actual photos (and not rainbow-colored depth maps). Unfortunately, their cameras were too expensive; their software buggy, and their workflow lacking any interoperability with existing photography tools. Who’s going to spend $1500 on a camera with a relatively small sensor, fixed lens, raw files not understood by ACR, requiring photographic skills no one yet has?
And thus the Lytro Illum didn’t “change photography forever” like some have predicted. It simply disappeared into the abyss of failed experiments. Its remnants, however, still remain, and the Illum can now be acquired for $250. At that price point, it’s an advanced toy that can be an entrance to lightfield photography for many, like me. $250 for a camera with a 1/1.2″ sensor, 8mm-77mm f/2.0 lens, highres tilting multitouch LCD, dual manual dials, standard hotshoe and lightfield capture, I’d say is a steal.
For what I do, this is a perfect second camera body.