New Focal Field System Can Alter Focal Length Later From Single Exposure
A new group known as the Focal Length Consortium is set to announce this coming Wednesday the forthcoming availability of the new Focal Field System that combines camera, lens and software to produce multiple images of different focal length from a single exposure.
Along with aperture and shutter speed, the choice of focal length is a key factor necessary in the creation of any photograph. Today, photographers can select from a range of fixed focal length lenses or choose a zoom lens in order to frame an image the way the envision. But once the choice has been made and the shutter release pressed, there's no going back. Nothing outside the angle of view of the chosen focal length will be captured by the sensor, and only what the lens can see will end up in the resulting image.
Focal length and field of view for a given lens are inversely proportional. Light entering a lens is initially collimated, with each ray travelling essentially parallel to the others. The lens works by converging the light rays to bring them to a point of focus. As such, focal length is a physical characteristic of the lens system. If you want a different angle of view, you have to use a different focal length lens.
To provide broader coverage and avoid limiting their options, some photographers employ a bracketing technique by shooting multiple frames while varying the lens focal length. This allows them to pick the version that seems best after the fact, without the pressure of being forced into any single focal length in the field. But bracketing can be a time consuming process and one many photographers have long wished they could avoid.
Apparently they aren't alone. For three years now a secret group calling itself the Focal Length Consortium has been working to change the rules of the game. The vision they have been working toward is the day when photographers can shoot without worrying about focal length and then create an image with the angle of view they want later in the digital darkroom.
The Consortium has invested considerable effort in their quest and is finally set to unveil their first patent. The text describes certain "new and useful improvements constituting optical system devices, computer software algorithms and integrated methods allowing for deferred selection of focal length." That's a mouthful.
The complexity of such a system is not to be taken lightly. Traditional camera systems only capture a single version of a scene in a frame. What would it be like if you could capture both the wider vista and the smallest area in a single shot? Any innovation that could achieve that aim would revolutionize photography.
At first glance, the existence of such software appears to refute the longstanding understanding that different focal lengths inherently exhibit different perspectives. Any beginning photographer who claims to be knowledgeable will tell you that wide angle lenses show an exaggerated perspective while telephoto focal lengths tend to compress perspective. And beginning photographers can't be wrong since this same information can be confirmed by countless internet websites and online discussion forums.
It's not entirely clear how the Focal Field System works but somehow by means of what the patent text refers to as "cropping" one can take an image shot at a wider focal length and trim all four sides by equal proportion to produce an image that has the identical framing of one originally shot with a longer focal length. Imagine taking a shot made with a 50mm lens and "cropping" it so that it comes out the same as one shot with a 100mm lens. And the trick works with any type of image regardless of subject matter or exposure.
Little is publicly known yet about the Focal Length Consortium, but they are made up from representatives of most of the leading camera manufacturers including Nikon, Canon, Tim Hortons and Radio Shack. All companies involved have extensive portfolios with some deriving a significantly greater portion of their revenue from photographic equipment than others. This has apparently resulted in internal squabbles that have provided at least some clues as to what will be announced come the beginning of the month. I'm admittedly jumping the gun a bit by publishing this article early so it's possible that some of this may prove not to be completely accurate.
On condition of anonymity, Mr. Primeiro de Abril, a general partner at the Consortium's offices in Tolos, Portugal has let it be known that the method also works with both jpeg and native camera raw files. So called "cropping" can be done with any image format. Camera makers participating in the Focal Length Consortium don't need to agree on a common raw format. Consumers are equally free to make use of the technique in the software of their choice. If the Consortium has their way, a tool for cropping images in software may become common to change the framing of an image.
Admittedly there is a significant loss of resolution from cutting off such a large amount of peripheral edge pixels but this can apparently be corrected by adding them back through upsizing the resulting image in Photoshop. Beginning photographers and certain websites generally agree on this point as well but details are still unclear.