Seeing double puts 3D on TV
3D imaging has come a long way since grandma's stereoscope.
THESE days you can get three dimensions for not much more than the price of two when it comes to buying a telly. So why settle for two-thirds of reality? And how do 3D photos stack up on the new display media? We consulted the aficionados.
Malcolm McCormick and Tony Bignell, of the Victorian 3D Society, demonstrated for us the present state of 3D photography on an LG TV, a ''passive'' system.
Between them, McCormick and Bignell have tried every camera set-up and every display device for stereo still imaging. Bignell, an engineer, has constructed rigs to hold two cameras side by side and to synchronise their shutter releases. McCormick is the master of ''cha-cha'' - taking one shot and then moving the camera horizontally to take the next. For creating stereo pairs, they use StereoPhoto Maker (Windows only, from stereo.jpn.org/eng/stphmkr).
We learnt a lot from the experts and set out to try 3D photography for ourselves, first for no cost and then taking the expensive route.
Any camera can make stereo photos that can be made viewable in StereoPhoto Maker (SPM). The basic method is to take one photo, move the camera 75 millimetres to the right and take the next. SPM will align the two images and turn them into a stereo file. Output can be anaglyph (viewed through red and cyan glasses), side by side for printing, or in the universal MPO format for 3D TVs and monitors.
There is a formula for lens separation for best results - the distance between lens centres should be 1/30 of the distance of the subject from the camera. For landscapes, this could involve quite a walk between shots.
Many current cameras have a 3D function in the scene setting. On some this works by taking one photo, which leaves a ghost image on the LCD, and moving the camera until the second image overlays the first. On others, 3D images are created by holding down the shutter button and sweeping the camera. In either case the saved image is an MPO.
SPM will arrange the two parts of the MPO file side by side and create an aligned anaglyph image that can be viewed right there on the monitor. You can post these images to a website or any of the photo-sharing services and hope viewers can lay their hands on a pair of red-cyan glasses. For $60, after a short search, we bought a replica of the Holmes stereoscope that grandma had. SPM prints a stereo pair card perfectly formatted for the Holmes viewer. It's low-tech but fun.
So much for 3D on the cheap - what about the state-of-the-art stereo image display gear? We set out with the Fujifilm Finepix Real 3D W3 (see box) camera to take our 3D photos and settled on a Samsung 3D-enabled computer (box) and a Samsung 3D TV to display the results. The camera creates a stereo image in widescreen, high-definition 1920 x 1080 pixels format, which can be displayed on a TV straight from the memory card.
A well-considered stereo image is spectacular. Displayed on the Samsung PC (see box), the best pictures are like looking through a window at the subject. And on the 137-centimetre Samsung ES8000 TV ($3700), images taken straight from the Fujifilm 3D camera are breathtaking. The Samsung uses the active 3D system and this gives us another variable to consider - passive or active viewing glasses.
Passive is cheap. The sets are cheaper and the spectacles are the same as supplied at a cinema, so the whole family can be fitted out for a few dollars. LG and Panasonic make passive systems.
Active is more expensive, both the TV and the glasses, which are battery-powered and synchronised to the TV display. But when we viewed a passive LG alongside an active Samsung, we preferred the active picture quality. The passive system works with circular polarisation of the image, which reverses polarisation line by line. This means fine black lines are discernible in the picture. Active images are flawless. However, many reviewers prefer passive - it's a matter of personal perception.
There are also personal 3D viewers made by Epson and Sony that look like Starship Enterprise army surplus that we find too enclosing to be attractive.
The downside of stereo imaging is that even the best 3D stills can appear as a set of receding planes rather than as fully rounded objects. And because it is difficult to get all the parts of the image at different distances from the camera to converge, the brain is working overtime.
Academy Award-winning film editor Walter Murch says: ''We can [force the brain to process images]. 3D films would not work if we couldn't. But it is like tapping your head and rubbing your stomach at the same time; difficult. So the 'CPU' of our perceptual brain has to work extra hard, which is why after 20 minutes or so many people get headaches … This is a deep problem, which no amount of technical tweaking can fix.'' There are other problems, more mundane, such as the darkening effect of the glasses on the picture.
If you are interested in the art and physics of 3D photography, you should seek out the 3D Society in your area. In Melbourne, the society meets bi-monthly in Deepdene (vic3d.org.au).