Lytro - No More Need to Focus

Reposting the post of John Friend CTO (multiple start-up guy) on the Lytro camera.

Thought it would be interesting

After reading parts of Ren Ng's (the founder of Lytro) PHd dissertationhttp://www.lytro.com/renng-thesi..., I would summarize the answer to my own original question this way. Possible photography advantages:

• Focus control after-the-fact (can decide what to focus on in post processing)
• Depth of field control after-the-fact (can decide whether you want narrow depth of field or high depth of field in post processing). Can potentially get larger depth of field, even while still shooting at large aperture (high shutter speed, low noise and large depth of field which is hard on a conventional camera)
• Larger depth of field might really be enabling for some kinds of macro photography
• Might be able to achieve lower noise because you have multiple samples of very similar views of the subject so some random noise might be able to be removed by comparing these samples
• Since the entire image is being built digitally from lots of little pieces, the image can be corrected for known faults in the lens (even more so than is done today with regular images)

Possible disadvantages:

• Lower resolution - 1/2x in each direction (the more refocusing power you have, the less resolution you capture)
• Aliasing artifacts
• Additional cost of micro lens array
• Additional post processing required to render desired photo

Here's my summary of the general technology from reading the dissertation. A micro-lens array is placed in front of a traditional photo sensor in a camera such as the one shown in the diagram below. This results in N small, lower resolution, images being recorded on the photosensor (one for each micro lens). Each of these images is taken from a slightly different perspective as each image represents lightrays coming from a slightly different angle. Computer software can then be used to combine all these different images in unique ways to provide different views of the scene (different focus points or different perspectives). This type of camera is called a plenoptic camera.