Nothing new behind the lens
Originally published 2005 in Atomic: Maximum Power Computing Last modified 08-Feb-2013.
A surprising amount of today's digital imaging relies on the same basic physics as did older, slower, more-likely-to-involve-trays-of-sodium-thiosulfate-solution technologies.
Take, for instance, 3-CCD video cameras.
Amateur and semi-pro videographers have been lusting after cameras with three sensors in them since Hi8 tape was the hot new technology, and with good reason. 3-CCD cams use a beam-splitter that delivers red, green and blue light to three separate sensors. The result is higher resolution and better colour rendition.
(3-CCD still cameras never took off, partly because the beam splitter for a large-ish sensor is not a small object, and also because sensor alignment and sensitivity matching matters much more in a high-resolution still camera that's capable of slow shutter speeds than in a low-resolution video camera that isn't.)
People have been taking colour photographs since Sergei Mikhailovich Prokudin-Gorskii (ask for him by name, accept no substitutes) did triple-filter shots of Russia about a hundred years ago. Anything that moved between the filtered exposures would end up a psychedelic blur, and he couldn't make prints, but he could project, with a three-lens slide projector analogous to recent three-tube CRT video projectors, some pretty cool pictures.
We had to wait a lot longer for movies using 3-CCD-ish technology, of course.
That took until about 1933. That was when "three-strip" Technicolor first hit the screen.
Technicolor used a beam-splitter, not entirely unlike that inside a 3-CCD camcorder, to deliver R, G and B to three separate strips of film. Those strips were then laboriously developed and combined and dyed and applied to a final clear (or, sometimes, black-and-white) film strip to create a multicoloured single final strip that a normal unfiltered single-lens projector could display.
(Modern colour laser and dye-sublimation printers lay pigments down in much the same way as the Technicolor combination process, by the way.)
The Technicolor rigmarole was difficult and expensive, of course, and lining up the colours was a bit of a bugger. There are the thick end of two million Technicolor frames in Gone With The Wind. Any volunteers?
(Today, you can buy a DVD made from digital scans of Technicolor negatives that looks better than the original movie did. This is partly because the digital process lets us line up the negatives better than the old print-makers could.)
But Technicolor nonetheless worked well, which is why it remained popular for so long after "single-strip" colour became available in the mid-'50s. There were still plenty of new Technicolor movies showing in 1970 (and later).
Now, your modern handy-cam is just a tad superior to the common home-movie formats of days past. Grandpa's 8mm film movies had no sound, VHS resolution at best, 16 frames per second, and a filming time per spool of less than four minutes.
But that doesn't mean that recognising the importance of the old tech, and even letting some of its look leak into modern life, is a bad thing.
Back in the 1920s, there was "two-strip" Technicolor, which only captured red and green - on one actual physical "strip" of film, running at double speed and being exposed and projected through separately-shuttered colour filters.
There was no actual blue at all in a "two-strip" movie, though viewers often thought they saw some, as their brains struggled to deal with all those brown skies.
Sky Captain and the World of Tomorrow looks somewhat like a two-strip Technicolor movie. The makers used Adobe After Effects plug-ins to create that effect, plus the soft focus that emulates old simple movie camera lenses. Why'd they do it? Because it looks cool, that's why.
Today, some people are using their expensive digital SLRs as pinhole cameras. Make tiny hole in small thin piece of metal, affix metal over hole cut in middle of camera body cap - or just put a little hole in the plastic body cap itself, and see how you go.
Pinhole projection is sixteenth century technology.
You can do soft-focus simple-lens photography with DSLRs, too. Wangle up some tape-and-rubber monstrosity with a bored-out body cap on one end and a plastic magnifying glass lens on the other. Or cheat, by using a Lensbaby.
It is, of course, fun and educational to muck about with this sort of thing, but there's more. You can't take pictures that look like pinhole exposures without a pinhole, and pinhole photos can look great. And you can fake soft focus and weird tilt-shift stuff, Lensbaby style, by playing around in Photoshop, but you can't stand there in front of a flower and play in real time without the actual hardware.
We've already got software emulation of rooms full of expensive old music equipment; maybe photography will go the same way.
In the meantime, though - get out your body caps and start pinholing!
