The technology behind the Lytro camera, light field photography, has never been easy to grasp. If you want to understand the optics, here's a good guide, but it's probably best to try to understand Lytro in terms of what it can do.
The first version, which came out this year, recorded photos that you could focus after they were taken. Like this:
Lytro called these "Living Photos," which is a marketing term but still apt — few people outside of the academy had ever seen anything like this.
The camera, which doesn't have a traditional lens/sensor arrangement, was an unusual block of a device that retailed for $400. It was, in my experience, a little hard to use, the photos were low res, and didn't do very well in low-light/fast motion situations. It felt, in other words, a little like a science experiment.
Lytro recently released a small update adding manual photo controls, including ISO and shutter speed, which helped. But this week's update is much larger. It doesn't affect the camera, which collects the same raw light data no matter what. Instead, it gives you new ways to process the light fields in the client software. Mainly it lets you do this:
Light field photos contain enough image data to create traditional 3D stereoscopic images, and then some. What you're seeing above is actual perspective shift — not a software trick. Here, try it out yourself by clicking and dragging:
The effect is even more profound when applied to humans:
Lytro has also added filters, some sort of Instagrammy and others straight out of Photoshop.
Perspective shift, far more than refocusing, sells the light field concept as truly different. There's an unsettling and powerful presence to these photos that you can't get from even a video.
The Lytro is still a niche device, and maybe even a toy. But it's toy that'll be worth buying for some people and a startling preview of what might, with a lot of engineering and a little luck, change what we expect from our cameras.