Lytro started in the consumer space a few year’s back by enabling light field camera sensor technology in a portable package. Back then it allowed the user to select the focus point in the image to control depth of filed after the shot had been taken. This is emulated by Panasonic on the GX8 and GH4 with Post Focus but that is a feature that does some tricks with multiple images and lens focus points to select final depth of field.
Lytro does this by capturing all the rays of light entering the sensor at different angles and times to create a light field or three dimensional map of a real subject or scene. The consumer cameras sold in less than stellar numbers due in part to low resolution and while they tried with the Lytro Ilum to bring a more SLR like camera with 40 mega-rays or down-converted to 4 traditional megapixels. It also bombed as the post focus feature was not enough pull to get consumers to adopt the platform; along with claims of low dynamic range and artifacts in bright spots. The Ilum camera is still available for purchase at under $370 USD from the 1299 introductory price; quite a drop!