Every time I hear someone say they really want a light field camera, I immediately think, oh, like a Tachihara? Me too!
But no, they're talking about
integral imaging. If both light field and integral imaging are terms new to you, join the club. The gist of it is some folks are marketing a digital camera that can capture the vector information as well as the color and intensity of the light, and can then reconstruct the image spatially. Normally this is pitched as allowing you to focus after the fact. Yep, read that again. You could also alter the bokeh, or (in this modern age) present a three-dimensional representation of the capture to the viewer. Other than archaeological or forensic work, I have trouble finding the practical value, but definitely something for the cabinet of curiosities, right?
It turns out the ideas behind all of this are almost as old as photography itself. I stumbled across
this article that resurects
hundred-year-old ideas about leveraging an array of lenses (in this case, pinholes) to capture an array of distinct views (think LOMO Action Sampler on steroids), then using the resulting array to reconstruct the light field.
Of course, a hundred years ago they weren't simulating a light field. It turns out, you can use what's called a fly's eye array to reintegrate those images into a composite view, and like a holograph your eyes will be able to focus on near and far elements in the, uh, image...capture...whatever you want to call the result. Clearly, not traditional photography.
The authors of the article were extremely clever, though. They used a digital back on a medium-format camera, slapped an array of pinholes over the sensor, and voila. I definitely did not understand the math regarding how the pinhole(s) between the lens and the sensor are able to resolve the image, but I believe them, and it occurred to me that you could probably cheat all the way around, ditch the digital gear, and reconstruct an integral image completely analog.
It seems like unlike big sheet
lenticular lenses that you might find in a children's toy, fly's eye lens arrays might be hard to come by. You can get them for about $20 per square inch on your auction site of choice, but unless you want to work with an 8x8 array of 3 mm x 3 mm pinhole images I think that's probably a non-starter. Initially, I thought if you took something like two Action Samplers, shot slide film with one, you might be able to butcher the other into something like a ViewMaster that would let you reconstruct the four views into a low-fi light field.
But, if you've already got a hybrid workflow going, and you're shooting 4x5 or larger, you could probably replicate the trick and put a pinhole array in front of the film holder, scan the entire sheet and spend a few hours chunking the results into...what? The world's best
wiggle GIF? Whether analog or digital, presentation of the results is the real stumper for me. It seems like if you could get your hands on a 4x5 or 8x10 fly's eye array, you could measure the lens distance, build the pinhole array to match, then shoot transparencies and light them from behind with the fly's eye array in front. The right subject with the right film, I think the result would likely be much more dramatic -- and interesting -- than its current digital counterpart. Whether it would be worth the couple hundred dollar investment in fly's eye arrays to experiment at 6x9, I'm not sure. My gut says either it will be mind-blowing or it will be lackluster.
Help me, Francois. You're my only hope.
The other bit of reusable fun from the
initial article is that they had the pinhole array printed, which I thought was a clever trick.
