3D Video Primer, Part 1

3D Video Primer: Part 1

How it began - the History of 3D Cinema

The stereoscopic era of motion pictures began in the late 1890s, when British film pioneer William Friese-Greene filed a patent for a 3D movie process. In his process, two films are projected side by side on a screen and the film is viewed through a stereoscope. In 1900, American inventor Frederick Eugene Ives patented a stereo camera rig which featured two lenses coupled together, and throughout the 1920s and 30s innovation was swift. The 1930s also saw the birth of polarized 3D, which remains the standard even now, more than 80 years later.

In the late 1960s, so-called 'Space-Vision 3D' was developed. In a 'space-vision' system, two images are printed one above the other, in a single frame of film and projected through a single projector fitted with a special polarizing lens. Careful synchronization of left and right channels became unnecessary (early on, badly synchronized 3D films were a huge cause of audience complaints), and footage could be presented in widescreen.

The arrival of IMAX in the 1980s revitalized 3D fimmaking, and until the dawn of the 21st century, 3D lived mostly in the special attractions realm, fuelled by IMAX's expanding 3D network. In 2003, James Cameron's Ghosts of the Abyss was released as the first full-length 3D IMAX feature filmed with the HD Reality Camera System.

In 2009, Cameron's 3D epic Avatar was released to great critical and audience acclaim, and heralded a whole raft of new 3D releases. More than 40 3D movies are scheduled to be released in 2011 – an unprecedented number in the history of 3D cinema, and the same number or more are projected for release in 2012.

Watching in 3D - Glasses on, or Glasses off?

Think 3D and you probably think of cardboard glasses with one green lens and one red. These are anaglyph 3D glasses, and belong to the earliest days of 3D filmmaking. Even during the first '3D craze' of the 30s through to the 1950s though, the anaglyph method was hardly used at all in theatres. For more than 80 years, the most popular way of viewing 3D has been using polarizing systems.

Polarized 3D has been the standard for color 3D video for decades. A major downside to polarized 3D systems is that the glasses block out quite a lot of light, reducing brightness. The footage has to be projected at a high brightness level to compensate, with the result that tonal range and color saturation is reduced.

The third glasses-based 3D viewing method is the so-called 'eclipse', or 'shuttering' system, where left and right channels are projected alternately on the same screen, and LCD 'shutters' in special lenses block each eye in turn, in sync with the display. Some light is blocked, but tonal range is wider and colors are more natural in a shuttering 3D system compared to polarization, and almost all 3D televisions use shuttering technology. There are downsides to shuttering though – the glasses are powered by batteries, so they are heavier and bulkier than polarizing glasses, and because of the technology built into them they are also far more expensive (for the moment). 

'Classic' 3D glasses are used to view anaglyph 3D film and images, which are perceived as monochrome. As such, anaglyph 3D works well enough with black and white images and footage, but can't provide a full-color 3D experience.
In a polarizing 3D system, two images are superimposed through different, mutually orthogonal (at 90 degrees to one another) polarizing filters. For the sake of clarity, this image shows two separate projectors, each fitted with its own filter.

The viewer wears inexpensive glasses that also have mutually orthogonal polarizing filters over each eye, with the result that the left eye only sees the left channel, and the right, the right. The brain then obediently combines the two images into one 3D picture.

Unlike anaglyph and polarizing 3D, where the left/right images are viewed simultaneously, in an eclipse, or shuttering system, they alternate rapidly so that the screen only ever shows a single channel at a time. To create a 3D experience, the viewer wears LCD glasses that 'shutter' each eye continuously and very quickly, in sync with the screen projection so that the brain is fooled into seeing a single unified 3D image.

Glasses off (Autostereo)

For obvious reasons, glasses-free, or 'autostereo' 3D is the holy grail of 3D imaging. Currently, there are two primary forms of autostereo displays on the market - lenticular and parallax barrier. Sony and JVC both use parallax-barrier screens on their 3D camcorders, and Sony offers an optional lenticular screen for some of its Vaio Laptops. 

In a lenticular 3D screen, images are displayed with the left and right channels interlaced in alternating vertical strips. Lens arrays are overlaid vertically on the display, which magnify the left and right channel 'strips' in opposing directions, so that at the correct viewing distance, the viewer's left eye sees only the left channel picture, and the right eye, the right, making a 3D image.
The principle behind parallax barrier screens is very similar. In a parallax-barrier screen, instead of lenses, physical barriers block the left/right channels when the viewer's eyes are aligned correctly with the screen.

One of the downsides of both lenticular and parallax-barrier screens is obvious if you've ever received a 3D postcard – if you move your head, or get too close or far away from the screen, the effect breaks down. Displays like this work reasonably well in portable devices like the Nintendo 3DS and Sony's TD10 because their screens are small, but scaling up is very expensive. Another issue is that both lenticular and parallax-barrier screens reduce overall image resolution, which has unpleasant consequences for the image quality of 2D footage. To compensate, any future big-screen autostereo TVs will need to have a much greater resolution than today's HD models.

3D Cinema: Go Out, or Stay at Home?

In the past, watching a movie in 3D meant heading out to the local cinema, but these days consumers have a choice. If you go shopping for a new TV, you'll see plenty of models that boast '3D compatibility', and as well as a growing number of 3D Blu-ray releases, 3D content is also available on several television channels worldwide. At the time of writing, the number of 3D channels is still small (15 channels globally, of which five are available in the US, and two in the UK) but if industry analysts are correct availability of 3D content will grow considerably in the months and years ahead.

This process will take time though, and right now, most 3D movies are watched in the traditional way – in movie theatres. But there are indications that consumers might not be quite so in love with 3D as the film industry has hoped they might be, and arguably needs them to be. According to Box Office Mojo and BTIG Research Estimates, 3D ticket sales flattened out in the first quarter of 2011. In 2010, 3D ticket sales totaled about 67 percent of the total box office revenue. As of early summer 2011, they were at 64.5 percent, a drop compared to the 2009-2010 increase of more than 5 percent.

After its release in 2009, James Cameron's 3D epic, 'Avatar' became one of the highest-grossing movies ever, eventually earning more than $2.6 billion at the end of its first theatrical release, and has been credited by many industry analysts with reinvigorating 3D filmmaking. A combination of computer-generated footage and live action, Avatar was filmed using stereoscopic cameras.

Price is certainly a factor. The cost of cinema tickets continues to rise, and watching a 3D release only bumps the price up further. Nick Dager, an analyst with the Gerson Lehrman Group as well and editor and publisher of Digital Cinema Report and IndieFilm3D feels that audiences have been simply been burned too many times by inferior 3D content. "Consumers are turning away from 3D movies when they don't believe that it adds anything to the story".

He could be right. It is certainly true that in the wake of the massive success of James Cameron's 'Avatar' - the movie credited by many analysts with reinvigorating 3D cinema - a lot of studios have found out the hard way that simply making a movie in 3D is not enough to guarantee huge takings at the box office. It is probably no coincidence that the 3D movies which garner the best critical reception (like Avatar, and DreamWorks' Kung Fu Panda 2) tend to be those that boast the healthiest 3D ticket sales compared to conventional 2D.

Despite some sobering figures, Andy Bubala, Sony Electronic's Camcorder Business Director is bullish. "We're going to be sitting around in 30 years trying to remember what 2D looked like" he confidently predicts. Whether or not he's right remains to be seen, but television and camcorder manufacturers, as well as film studios, are certainly banking on the enormous potential of the new technology.

In Part 2 of this article we'll be looking at consumer-level 3D video and stills, and the success (or not) of the major electronics manufacturers in getting 3D into consumers' homes.

Click here to read Part 2 of our 3D Video Primer 

Barnaby Britton is Reviews Editor of dpreview.com. Valentina Valentini is a freelance journalist based in Los Angeles. You can see more of her work at her website, www.valentinavalentini.com


Total comments: 31
By mbloof (Sep 21, 2011)

3D - the success or failure of it lays in the hands of those that capture it (or not) and those that present it.

I remember seeing 'Avatar' as it was the 1st 3D feature where the 3D effect 'worked' for me. Almost all in theater features I've seen this year were in 3D, some were better than others for different reasons.

Is it to much to expect to see a 3D feature when your paying for it? Of the titles that I was least pleased with I could count on one hand the number of 3D scenes scattered through a 2D film. Many of the titles were 'conversions', features that were not shot in 3D - but converted later - and only portions of it were in 'simulated 3D'. There were a few 'conversions' that worked well and a few 'shot in 3D' that might of been, but what was presented on screen was not.

When captured and displayed well 3D can be awe inspiring.

1 upvote
By GrahamD (Sep 20, 2011)

Our brains are very clever; we can watch a black and white movie and interpret it as if it were colour (i.e., we don't think of people as having grey faces). Similarly, we can watch a 2D movie and interpret it as 3D. But we cope better with missing information than wrong information. Watching black and white is OK, but watching something with the wrong colours is not. Just shift the hue setting on a software movie player. Grey faces are OK, but purple or green won't work. Similarly, 2D is better than wrong 3D and 3D is only right when the viewer's angle of view is the same as that of the camera (with appropriate image separation). Most people sit too far back from a TV, so will see everything in miniature. Directors will have to sacrifice the flexibility of wide angle and telephoto zoom shots and shoot everything with a standard lens. If they need to get close to the action they'll have to move the cameras in. So 3D is great if you get it right, otherwise forget it.

By Trike (Sep 19, 2011)

This is fairly interesting, but it's becoming increasingly evident that 3D is a fad that is already waning. People are staying away from 3D movies now and 3D TVs (and video game devices, apparently) aren't selling.

By all means, keep doing articles on it, just keep in mind that it's going to return to being a niche market. (Forever, if I had to guess.)

By N13L5 (Sep 20, 2011)

I think there are 2 main reasons for the lack of uptake:

1) there's a healthy price premium on a 3D TV, vs last year's 2D models. Basically, in the stores, you're able to buy a 55" 2D TV at the same price point as a 40" 3D TV. Even the added benefit of loosing that hideous piano lacquer with the newest models seems to have a hard time making up for a several hundred dollar difference :P

2) You need to wear those glasses for anything in 3D, so uhhh, who's gonna sit around their house with those glasses on for regular TV?? People might put them on for a movie or a game, but the rest of the time? David Letterman in 3D? its just superfluous for a most programs.

Once they figure out how to do 3D without glasses and without having to sit still in the "aligned" spot, it'll become ubiquitous, just cause we need the product upgrade carousel to keep going round and round.

Personally, I'd be more interested in a device that can visualize four or five dimensional space.

inevitable crafts studio
By inevitable crafts studio (Sep 14, 2011)

great article

Cy Cheze
By Cy Cheze (Sep 13, 2011)

The greater share of what we perceive as depth has nothing to do with having two eyes or lenses, but size, overlap, and paralax. All are possibly with single-lens photography. In the case of video, there is also the factor of perceived differential motion: the moon that hovers "stationary" over a slow "moving" landscape, as objects next to the road "race" by the car window. That, too, can be achieved with a single lens camera.

1 upvote
Cy Cheze
By Cy Cheze (Sep 13, 2011)

Stereo vision or imaging can add to the perception of depth, but isw probably the least effective of all, while being the most expensive and cumbersome. It takes lots of extra money and trouble to shoot and edit a 3D video, or to create and share a 3D print, but the effect is hard to perceive if the objects are more than 30 feet away. Unless you employ an inter-ocular distance much greater than that of the human eye, a football game shot from the upper row of a stadium will look the same whether you use 2D or 3D mode. The 3D mode will look worse, too, if it requires more light or limits the camera functionality.

A year after Panasonic introduced 3D adapters for some videocams and cameras, the firm still has not offered an encore for 3D sports or outdoor work. The two apertures are too close to convey 3D for anything but kiddies at play in front of you.

Morgan David
By Morgan David (Sep 14, 2011)

"It takes lots of extra money and trouble to shoot and edit a 3D video". If everything in life was easy, there would be no more need professionals...
And of course your brain can imagine the depht by seeing the moon moving slowly and the foreground moving fast, or just remembering that the moon is always far away, so the other objects must be in front, but he can also imagine the color of the sky, the skin, the grass...
So I suppose you are only watching black & white movies from a 16mm projector at home, or an 8mm... who needs definition... your brain knows that there are leafs on a tree anyway.

I believe that good 3D shot by great stereographers and projected by professionals or seen on good 3D TVs is magic! And seeing footbal or golf in 3D is even more magic since for once you understand precisely where the ball is going.

(excuse my English)

Zhiyong Sun
By Zhiyong Sun (Sep 13, 2011)

Can't wait for the second part. Great article!

Ian Johnston
By Ian Johnston (Sep 13, 2011)

IMHO, 3D in the home may die a death or at least be postponed at the hands of the Tv manufacturers. Fair enough the high end, expensive, Tv's provide great 3D, but they push the technology into the cheaper sets and as a result you get ghosting and a less than ideal 3D experience.
LED Tv's are the worst since the LCD technology just isn't yet fast enough.
Samsung take note!!!!

Morgan David
By Morgan David (Sep 13, 2011)

:) "We're going to be sitting around in 30 years trying to remember what 2D looked like" I really hope she is right!

For stock photographers/filmmaker willing to try something with 3D:
We have created a 3D stock footage marketplace called Stereobank.

If anyone wants more info, don't hesitate to contact me on morgan@stereobank.com


By N13L5 (Sep 20, 2011)

I guess this explains why you thought 3D is so overwhelmingly wonderful in the other response.

But really, I think you went way over the top with your 8mm black and white film parable. But people selling things always go to great lengths to make their product look indispensable...

I guess in 30 years, its gonna be a brave new world for painters... paintings will double in price, cause the poor slobs have to paint everything twice...

I hope people remember they get the best 3D, if they just go out and play some tennis or whatever they like themselves, making their lives their own movie. Or else, we'll all end up as brains and eyeballs floating in a nutrient solution in a jar - entertained into oblivion.

Bob from Plymouth
By Bob from Plymouth (Sep 13, 2011)

In response to Mike Davis:

I saw the last Harry Potter film (Deathly Hallows Part 2) in 3D and I thought that director David Yates did a fair job of not making the 3D too obvious. it was toned down quite a lot compared to Cameron's Avatar.

The only over-the-top 3D at this screening was in the adverts shown before the movie, as you might expect.

It's like anything new, it gets overdone at first until people get used to it. A bit like colour TV back in the early days when most receivers were very oversaturated, or early stereo sound with an exaggerated width.

By Farneyd (Sep 13, 2011)

Wikipedia features a very elaborate article on '3D Film', the 'History' section starts like this:
"The stereoscopic era of motion pictures began in the late 1890s when British film pioneer William Friese-Greene filed a patent for a 3-D movie process. In his patent, two films were projected side by side on screen. The viewer looked through a stereoscope to converge the two images. Because of the obtrusive mechanics behind this method, theatrical use was not practical.[19] Frederic Eugene Ives patented his stereo camera rig in 1900. The camera had two lenses coupled together 1 3/4 inches apart."
Comparing this to the start of dpreview's article makes me wonder.

1 upvote
Barney Britton
By Barney Britton (Sep 18, 2011)

Makes you wonder what? That we used Wikipedia when researching this article? One of - perhaps the - biggest information repositories on the web?

By Farneyd (Sep 27, 2011)

Using when researching is something else than copying parts and changing a few words. I really do like DpReview, and look at the website on a daily basis, yet in this case I feel cheated by DpReview.

Mike Davis
By Mike Davis (Sep 13, 2011)

The biggest problem with 3D remains that which has always plagued it: 3D cinematographers, even the likes of James Cameron, are themselves so novice to the wow factor offered by the medium that they end up shooting in a way that exploits the technology to excess rather than gently and naturally integrating steropsis into their storytelling.

Those of us with healthy vision walk about all day every day seeing in stereo. 3D movies should be experienced the same way - as a natural experience - without excessive depth or having things poked in our faces. Five minutes into the film we should be able to forget that we're watching a 3D movie. 3D movies will be here to stay only when leading cinematographers can get past their own personal infatuation with the medium, do their homework, and stop experimenting at our expense.

The story is everything. Less 3D is more 3D.

Cy Cheze
By Cy Cheze (Sep 13, 2011)

If it costs 3X to make 3D, why make it so you don't notice? Kids who attend movies like non-stop chase scenes, acrobatic fights, careening objects, heroic leaps, explosions, and even the hands that reach out from the screen. Much of the 3D is digitally synthesized Pixar stuff, since 3D cameras in "real" settings don't convey much stereo unless the subject is very near. Sports 3D looks pretty flat unless the camera is very close to the sideline or goal.

Simon Zeev
By Simon Zeev (Sep 13, 2011)

Is about 2 years when I discover the anaglyps method and I shoot 3D pictures.
I try also small clips. The 3D effect is wonderful, but a lot of people cannot see the
effect or have problems (like headache)
Another method to see 3D pictures is "side by side" but few people can see the 3D effect and the 3D picture is 1/3 linear than the full screen.
I think that the 3D photography will have a good future.
-- Playing a game in 3D doesn't add more to the action and looking with red-cyan glasses make the viewed image much darker and loose the colors.

By Cheezr (Sep 12, 2011)

it took me less than 60 seconds to confirm my belief that the Nintendo 3DS does in fact use a parallax barrier and not a lenticular screen as stated above. Hopefully, the rest of the article is better researched...

Lars Rehm
By Lars Rehm (Sep 13, 2011)

Thanks, this is corrected now.

1 upvote
Barney Britton
By Barney Britton (Sep 18, 2011)

My mistake, thanks Lars for correcting it.

By Snapshot7 (Sep 12, 2011)

I felt this FIRST PART served its purpose. It gave an initial overview of past and current 3D technology from a limited perspective.

I look forward to the next parts that will no doubt, provide additonal and more detailed information.

By Mirek028 (Sep 12, 2011)

An interesting article, but no mention of spectrum division systems as used in Dolby 3D cinemas?

By Farneyd (Sep 13, 2011)

I agree very much with this remark. I recently saw the movie Pina in dolby 3D, and this was my best 3D experience. Reason is probably that there is no discernable darkening of the picture, as most other systems that need glasses do have.

By Mirek028 (Sep 13, 2011)

Not to mention that polarizing glasses may exhibit ghosting, something which is not an issue with spectrum division systems... on the other side, the issue of accurate color reproduction is present there.

D.R. Walsh
By D.R. Walsh (Sep 12, 2011)

I was disappointed by this article. It explains 3D from a viewers perspective, but on DPreview, I expected that the article would move on to the options and issues issues involved in recording 3D yourself.

By jakentta (Sep 13, 2011)

My thoughts exactly. I was expecting some good information about the best capture devices, the ways to edit 3D content and how to save and distribute it. I can't really see what this article has to do with the usuall DPreview focus areas.

Simon Joinson
By Simon Joinson (Sep 13, 2011)

there's more to come

By Nate21 (Sep 12, 2011)

thanks for the information dpreview.com very formal information and well laid out article

By jcuknz (Sep 25, 2011)

As I remember the fifties when I first saw 3D and was enthused by it at the time it was only in specialist theatres such as the National Film Theatre on Southbank in London that was using polarised glasses and 'Hollywood' was using red and Green glasses in larger theatres. So it was with considerable delight that I found a polarised system being used in my local cinema during a recent film festival.

Total comments: 31