Panasonic 12.5mm f/12 LUMIX G 3D

SLRgear Review
February 7, 2011
by Shawn Barnett

Reviewing a 3D lens naturally requires the hardware--TV and glasses--to view the effect, as the back of the current Panasonic cameras do not serve to show you 3D. So along with the new 12.5mm lens, Panasonic sent us a rather large plasma display, the TC-P50GT25 50-inch TV, and a couple of pairs of TY-EW3D10U battery-operated 3D glasses. Working together, the TV and glasses deliver an alternating 60 frames per second to each eye, which means that the TV puts out 120 frames per second, total. Called Active Shutter, the technology is universal to current 3D televisions, but it seems the brand of glasses needs to be matched to the television.

We shot a number of images of different subjects, including trees, dogs, kids, buildings, and cars. That gave us a pretty good feel for what the Lumix 12.5mm 3D lens could do. Though the active shutter technology built into the TV is optimized to deliver smooth video, according to marketing materials, the Panasonic GF2 does not produce videos with the 12.5mm 3D lens, only stills. The lens is also only compatible with the G2, GH2, and GF2 Micro Four Thirds cameras; currently no Olympus Pen Micro Four Thirds models support the lens. The camera can be set to record just the 3D image in MPO (Multi-Picture Object) format, or else the MPO plus JPEG in fine or compressed formats. Note that the resolution of the JPEG captured is 1.4 megapixels (1,600 x 904), because the lens is just laying down two images side by side on the camera's sensor. The MPO is essentially the same times two, so don't be expecting lush 12 or 16-megapixel images; the 3D images from this lens are intended primarily for electronic viewing.

ISO-Standard Dog. Charlotte the dog sat for the rare static photo, but only when she heard it was 3D. She fairly leaps from the screen in this sharp shot.
Download MPO file to play on a 3D television.

While using the lens was fun, we were quickly disappointed with a few aspects. One is that the very small, and fixed aperture of f/12 limits your shooting to bright daylight. The lens is hyperfocal, meaning that you don't need to focus. Objects from 1.97 feet (60 cm) to infinity should be in focus in all shots; that's really what you want for 3D, so no foul there. And though it's a 12.5mm focal length, the angle of view is actually quite a bit narrower than a 12.5mm lens would be with any other MFT lens, again because it's projecting two images side by side on the sensor (it should be a 25mm equivalent). Panasonic calls it 65mm equivalent at 16:9, and we'd have to agree. That kept us backing up quite a bit to frame images, sometimes quite a distance. So not just bright daylight, but preferably flat, open spaces are necessary to take advantage of this 3D lens.

What's noteworthy is that Panasonic was able to deliver 3D imaging in such a small lens. 3D as we're used to seeing it, however, is made with eyes that are separated by about 60-70mm (depending on the person), compared to this lens's 10mm separation. This explains the lack of depth that we often perceived on the television.

Vehicles. To my eye, the vehicles are mostly 3D, but without the proper depth. The trees in the background are mostly flat.
Download MPO file to play on a 3D television.

I happened upon a nice day in mid-winter, and took a few shots of the kids outside, then piled them in the van for a trip to the office where we could see the pictures in 3D. I'm blessed with a yard that is big enough to zoom with my feet, and I found myself having to back off as much as 20 or 30 feet to frame images the way I'd normally do with a zoom, just to get two small kids in the frame. I also crouched down much of the time to allow for plenty of background in the pictures. I had the sense that I could see some of the 3D effect on the Panasonic GF2's screen after capture, almost certainly an illusion, but it wasn't until we got to the big 50-inch television that the images really popped.

Children. Most shots of the kids were well-defined from the background, but that background tended to curve up rapidly behind them to my perception.
Download MPO file to play on a 3D television.

Some of them, anyway. Whether an image popped really depended on the lighting and the distance between me, the subject, and the background. In fact, it seems that objects about halfway between the camera and the background stood out the most, an observation made by my oldest daughter. All three kids seemed to enjoy seeing themselves at first, and they fought for the two sets of glasses, with me fighting right along with them so I could have a glimpse, too. After about 10 minutes, though, the interest faded, and the younger boys wandered off to explore the office, while my daughter took the glasses off altogether, only putting them back on to see what I was talking about as I continued to rifle through the images. She was getting nauseated, and the glasses hurt her eyes. To be fair, she said she was nauseated before we got there, and it turned out she had a stomach flu after all. But the boys also said the glasses bothered their eyes after a few minutes of viewing, and when their sister freed up her glasses, they were not interested in coming back to see more (my youngest son refuses to watch 3D movies at the theater, so it's impressive that this Panasonic TV held him as long as it did).

Publisher Dave (who's notoriously sensitive to motion sickness) also reported some queasiness when viewing 3-D images. He thinks it's caused by the way the scene position appears to shift when you move your head. If you don't easily become seasick or just don't move your head much while viewing, this may not be a problem for you.

Depth. This shot of the small truck should show what I mean with the lack of depth going back when viewed in 3D.
Download MPO file to play on a 3D television.

My eyes were slightly bothered by viewing the images at first, but I think I could get used to the glasses and TV. I was surprised that you could still see 3D fairly well as much as 45 degrees off-axis, unlike the passive 3D glasses I've used in the past. Each of the lab viewers experienced more or less 3D effect depending on the person. People with a very dominant eye might see no effect at all. I tended to see more than most, but I noticed a limitation: backgrounds often seemed to wrap back up toward the camera, rather than continuing cleanly back as I knew they should. As a result, you get the effect of paper cutouts against a steeply sloping background, rather than full depth. The 3D experts around me say it's likely the small 10-millimeter separation between the lenses that causes the perceived compression, not so much the 65mm-equivalent lens. Another flaw in the viewing experience was that dark objects against a light background tended to show ghost images overlaying the dark portions, especially noticeable in people and tree trunks. This is likely the result of the glasses not completely blocking light when in the "off" state: Some of the other eye's image leaks through, making the ghost images appear where a dark foreground object is next to a light one or vice versa.

The images were realistic enough that I found myself shifting my head to see if I could see more of a scene by moving to peek around a real opening into 3D space. When you do that, though, the 3D background just appears to float, unmoving, behind the foreground objects, an odd, somewhat unsettling phenomenon that caused a couple of viewer's queasiness.

Lab shot. Here's a tighter-than-usual shot of the INB indoor test target that should also show some depth.
Download MPO file to play on a 3D television.

Since we had the big, beautiful Panasonic 3D TV in-house, we also viewed a few images from the Sony NEX-3 made with the 3D Sweep Panorama function, as these are also MPO files. Results were good, with perhaps a bit more depth. But because the images are stitched from multiple images, it was really obvious where the stitching errors were made, because things like bunches of trees, which are considerably more difficult to stitch, would stand out as not conforming to the 3D world; one tree even popped out from the background to appear to be in front of the trees it was most certainly behind.

While I enjoyed looking at the 3D images for the novelty, I don't think it's something I'd do very often. Given how little time the kids looked at it, I'm sure I won't be an early adopter of the technology, even though the television Panasonic sent us currently sells for about as much as a 2D 50-inch TV cost last year: around US$1,050 at current street prices. (And the TC-P50GT25 is a very, very good 2D TV as well, with great color, excellent dynamic range, and very fast refresh.) The glasses are about US$100 per pair. Those already invested in 3D, be it for gaming or movie viewing, will likely find the US$250 lens an inexpensive way to enjoy the hardware they already have, provided they also already have a Panasonic G2, GF2, or GH2. (Those same users might also see it as additional reason to buy into the whole Panasonic Micro Four Thirds camera lineup as a whole.)

Still, I'm glad I have some photos of the kids playing in 3D, because someday the technology may be as ubiquitous as the once-futuristic flat panels are today. Indeed, some of what we saw at CES 2011, especially glasses-free 3D, made even the most skeptical 3D doubters among us start to wonder. Perhaps instead of continued confinement to the iconic reels of the 72-year-old Viewmaster stereoscopic viewer, 3D might finally stick around, what with electronic capture and electronic display technology finally becoming the mainstream method of image creation and consumption. Meanwhile, if you want to start capturing 3D now, the Panasonic 3D lens is available for current or future G2, GF2, or GH2 shooters at a reasonable price.