The big camera companies make plenty of fabulous models. What they don’t do is make ones that aim to reinvent photography from the ground up. It took startup Lytro to do the job, with the first consumer camera based on light-field technology. The $399 pocket-sized rectangular tube captures all the light rays in a scene, then lets you create and share “living pictures” which can be refocused after the fact. It won’t replace your point-and-shoot camera, or even the camera in your smartphone. But it’s a blast to play with — and utterly unlike any other photographic instrument you’ve ever used.