In 2012 California-based Lytro shipped the first consumer-orientated light-field camera. Alex Boniface explains why the technology has the potential to herald a major revolution in the imaging industry
Images captured using light-field techniques can provide photographs whose focus, exposure and depth of field are modifiable afterthe image has been taken. The commercial implications for this are huge, however before we consider these, lets examine the science.
Both analogue and digital cameras produce two-dimensional images by combining & focusing all of the light-rays that enter the lens onto the sensor. As a result of this process, images have a fixed point of view and the focus is determined exclusively by how the lens was configured at the time. Crucially, what is lost in this process is the directionalinformation as to which position the light rays originated from.In stark contrast to their digital and analogue counterparts, the Lytro camera is able to determine the exact location, direction and intensity of every single light ray hitting the sensor. This means that after the image is taken, the photographer has the ability to generate every single possible depth of focus that was taken within the field of view at that time.
Here’s how it works:
As opposed to the traditional digital camera hardware configuration whereby a sensor sits behind a main zoom lens, the Lytro engineers placed an extra sheet containing thousands of microlenses between the main zoom lens and the digital image sensor.
As light rays from different directions enter the lens, they are first projected onto the thin sheet of microlenses. In turn, each microlens projects a tiny, unfocused image onto the main imaging sensor. By employing this technique, the camera is able to identify both the angle and position of each light ray in a single exposure.
Instead of having to adjust the length of the lens to achieve a desired focus, the Lytro camera is able to generate images analogous to any ‘separation’ between the lens and the sensor as it is able to calculate the light-field at any given plane.
Generating (two-dimensional) images out of this three-dimensional data requires a huge amount of computational processing. The Lytro camera is fitted with a chip called the ‘Light Field Engine 1.0’ that processes the light ray data, and enables a photographer to refocus pictures right on the cameras built-in LCD screen, as well as on desktops and online. The Lytro engineers also substituted many of the internal parts of regular cameras with powerful software, introducing new
capabilities that were never before possible. Lytro note that by relying on software rather than physical components to generate images, the speed of actually capturing an image is dramatically increased whilst concomitantly creating opportunities for further camera lens, control and design innovation.
The user-interface is also incredibly simple; just a power switch, a zoom and a shutter button. After you have taken a shot, the image is displayed on the built-in screen in a matter of seconds. You can then tap anywhere on the screen to adjust the focus of the image. The photographs can also be viewed within their custom Mac desktop software, or uploaded to the Lytro servers where they can then be shared on social media sites.
So what about the implications for commercial photography?
Professional photographers shouldn’t be too worried yet, indeed, the company is still in its infancy and light-field technology certainly has a long way to go. The biggest problem facing the commercial uptake of light-field cameras is the fact that the cameras produce images in very low resolutions, 1.2 megapixels to be exact. Consumers have come to expect a minimum of at least ten megapixels from not only their digital cameras, but also their smartphones.
However once the resolution issue has been resolved, the stock industry could be transformed by this technology. The fact that image buyers can choose their desired focus after the image has been captured will revolutionise how professional photographs are consumed. And considering that Lytro expects to soon be announcing motion functionality, higher-resolutions, 3D parallax and ‘all-in-focus’ images, the implications can only going to become greater.
In fact, in Adam Lashinsky’s book ‘Inside Apple,’ he claims that Steve Jobs had shown a great interest in the technology and requested a meeting with Lytro’s CEO:
‘The company’s CEO, Ren Ng, a brilliant computer scientist with a PhD from Stanford, immediately called Jobs, who picked up the phone and quickly said, “if you’re free this afternoon maybe we would could get together.” Ng, who is thirty-two, hurried to Palo Alto, showed Jobs a demo of Lytro’s technology, discussed cameras and product design with him, and, at Jobs’s request, agreed to send him an email outlining three things he’d like Lytro to do with Apple.’ (Book quote taken from this post on 9to5Mac).
So where can I buy one?
Well here’s the bad news. Currently, the Lytro camera is only available to purchase in the US, Canada, Australia, Hong Kong and Singapore. For anyone else, you will have to sign-up to Lytro’s notification emails, or, begin a rather laborious process of buying the camera from the site, shipping to an address in the US and then arranging re-shipment from there.
We wait with bated breath.
To find out more about Lytro, and the science behind ‘living pictures’ visit the company’s blog.
For the real tech-geeks amongst you, the CEO’s PhD Dissertation on Digital Light Field Photography is available to read here.