The next big thing in cameras can't be measured in megapixels or lens elements. From now on, the best camera you can buy will be the one with the best algorithms. Whether you're playing with Portrait Mode on the iPhone, stitching together huge 3D images from the Light L16, or goofing off in augmented reality, all the hard work in your pictures now happens after you hit the shutter. For a couple of ex-Instagram employees, this presents an opportunity.