Posts Tagged ‘depth of field’
by Gwyn Headley
The New Year is traditionally the time to herald new things, starting with the Epiphany of the Christ Child on January 6th and the chance to play and replay my Desert Island carol, Peter Cornelius’s “Three Kings from Persian lands afar”.
So a happy New Year to you all. At my age things no longer occur, they tend to recur, and it’s rare to encounter something that appears to be completely new. Continuing the religious references, the Preacher in Ecclesiastes thunders “Is there any thing whereof it can be said, See, this is new?”
What I’m writing about today is a camera. That’s not new. But a light field camera is new to me, that’s for sure.
A light field camera? A field camera is one of those bulky great things with bellows, a permanent tripod, and a hood so the photographer can view the upside-down image on the 10×8 plate in darkness. Great for architectural photography, less useful for sports.
A light field camera is nothing like that. ‘Light field’ is the word phrase, and it refers to the way the device captures light data. The ‘light field’ is defined as the light travelling in all directions through all points in space. In conventional cameras — digital or film — the image (or light data) is captured on a flat plane at the back of the box. This can either be film or a digital sensor. The rays of light are combined and recorded as a single unit of light and shade.
In a light field camera, it is claimed that its sensor can capture the colour, intensity and vector direction of all the rays of light in a scene, providing much more data from which to compile an image.
What does this mean? Well of course the science is beyond me, but what I really need to know is what does this mean for the photographer, and obviously as a picture librarian, for image sales? In what way is the resulting picture different? Note that I didn’t say better. It’s not a field camera, after all, which is the gold standard for image quality.
My first thought is lots of data means big file sizes. And what do we do with all that extra data? The answer is nothing, at the moment. We’re back to 1950s Britain, where you couldn’t buy garlic or olive oil because “there’s no call for it.” At the moment, there is no call for it — there is no commercial need for the additional data a light field camera can produce. Here in 2012 fotoLibra has the ability to supply 8 bit, 16 bit or 32 bit images; we can supply HDR images. We don’t, because we’re not asked for them. At the moment professional picture buyers are content to buy 8 bit JPEGs.
I didn’t see the point of an HD television until I got one. But I can totally see the point of a professional quality light field camera to create images of record for museums and archives. Imagine being able to focus and study every plane of Nefertiti’s head. Wow.
Because here is why an image taken on a light field camera is different. You can refocus on any part of the image — after the picture has been taken. This is not the same as an Ansel Adams image at f64 where every part of the image is pin-sharp; these are images taken at f2 with a very shallow depth of field — which you can subsequently vary at will.
It is fascinating. I can play with these images for hours.
A light field camera has just been launched for the consumer market in the United States. Its brand name is Lytro, and I guess that could go the way that Hoover and Biro (and Kodak once did) to become the generic name for a light field camera. The first Lytro has an 8x optical zoom and an f2 aperture lens. It doesn’t look much like a camera, more like a square tube, and it comes in three colours and two storage sizes, 8 GB and 16 GB — 350 or 750 photos. It costs $399 (£255, €206) and $499. The aperture stays constant across the zoom range, which allows comprehensive light capture in the foreground, the mid ground and the background. The images it produces are 1.2MB JPEGs, which are at the lower end of the quality scale.
Do I want one? No, not yet. Remember, I’m not a photographer, I’m just a bloke who has a camera. Will it be more than just a curiosity? It’s hard to say. It’s certainly cheap enough for many people to be able to buy on a whim and play with, experiment with. Would I recommend you get one? If you’re a curious and inquisitive photographer who’s not strapped for cash, then yes, definitely. I would love to see what real photographers can achieve with such a tool.
At the moment the Lytro doesn’t meet the fotoLibra quality standards set out in our Submission Guidelines.
But I think we’ll make room for it.
Even though ‘There is no new thing under the sun.’