UFAlien's Stereoscopic Spectacular!

[UFAlien]

I'm sure that everyone here has heard of stereoscopic 3D, also known as S3D, 3-D, or just 3D. Lots of movies, games, and theme park rides are available in this format. This handy dandy guide will offer you some insight into the world of 3D.

 

WHAT IS IT?

 

A native 3D image in anaglyph format. Taken by me.

 

Stereoscopic 3D is a format that simulates human vision by providing two different viewpoints of a photographed or illustrated visual - one for each eye. Depth perception works in the real world because each of our eyes sees a slightly different view of whatever's in front of us. Our brain merges these images together so that we can perceive the third dimension. Traditional cameras and screens offer only one viewpoint, meaning that the image appears flat - our brain is aware everything in the image is the same distance from the eyes. Stereoscopic 3D material provides a different view for each eye, which fools the brain into perceiving depth.

 

HOW DOES IT WORK?

First, 3D content is created, whether it's drawn, rendered, or photographed from two angles, or captured in 2D and then converted. To display stereoscopic 3D, each eye needs to see only the image intended for it. That's where the glasses (or other techniques) come in.

 

HOW DO I VIEW 3D?

There are many ways to view 3D. One of the more common is called the Anaglyph format. This is how most 3D DVD releases are encoded, as well as some Blu-ray Discs and TV showings of 3D films. The video or image is encoded so that the differences between the two views are represented as two different colors - usually complementary colors. Some common color combinations are red & cyan, red & green, magenta & green, or blue & yellow (which is called "ColorCode"). By wearing glasses with lenses of corresponding colors, the correct image is presented to each eye. Anaglyph can be shown on any color screen, but can distort the original colors of an image.

 

The way most movie theaters show 3D - whether today or in the previous 3D booms of the 1950s and 1980s - is in a polarized format. Some common brand names for this are Real D and Dolby 3D. This preserves the original colors much better than anaglyph formats. Two images are projected onto a specially-coated screen, each with light that has a different polarization. The glasses you wear have polarized lenses which, just like the colored lenses in anaglyph glasses, ensure only one image is displayed to each eye. There are also 3D polarized televisions, typically referred to as "Passive 3D" TVs. These use the same technology as the movie theaters, and are often actually compatible with the 3D glasses from cinemas. However, current polarized television screens aren't full HD - each eye's image uses half of the screen's resolution, which can lead to a noticeable loss of detail when viewing 3D content.

 

Although rare in cinemas, active shutter 3D is common on 3D televisions and can also be used on older CRT televisions with special equipment. This system doesn't display both images at once; instead the left and right eye images are switched back and forth rapidly. Special battery-powered glasses are used to view this content. The lenses are actually little transparent LCD screens that can turn black and block your view, like closing the shutter on a window. These electronic shutters open and close in sync with the images on screen, meaning each eye only sees the image intended for it. The switch happens so fast that it's imperceptible.

 

The rarest form is parallax barrier technology. Think of lenticular cards - those shiny surfaces that change a picture depending on the angle at which you view them. The concept is nearly identical - physical mirrored barriers direct light into a specific eye, "projecting" the correct image into each. This method is used almost exclusively in small devices like phones, cameras, and Nintendo's 3DS. This is because there are VERY limited angles from which you can actually view the 3D content. If you scooch over, tilt your head too much, or move the device, the illusion of depth is ruined. The upside, of course, is that no glasses are required.

 

HOW DO I GET 3D CONTENT?

The simplest method is probably just to find a theater near you! 3D movies are still quite popular, and at the time of this writing, 3 of the top 10 American box office movies are in 3D, with another one opening this weekend. Many theme parks also have 3D rides and attractions. For home viewing, many 3D movies are available on DVD in anaglyph format. There are also some you can buy in active shutter formats, but these require special conversion boxes. 3D televisions are becoming more and more affordable. If you have one and the glasses that go with it, many digital cable or satellite providers offer 3D content both in the form of special channels and on demand. If you have a PS3 or a Blu-ray 3D player, you can also watch those releases in either polarized or active shutter 3D. Some PC games are playable in 3D with special equipment and software from Nvidia. There are also some PS3 and Xbox 360 games that work with 3D TVs. Finally, all 3DS games are in 3D on the glasses-free screen.

 

SO YOU SAID SOMETHING ABOUT CONVERSION...

Yes. Many movies and images originate in 2D and are later converted to 3D. There are varying methods with which to accomplish this. "Automatic" 2D to 3D conversion does exist and is built into many TVs, but at the moment it is of a very low quality and reliability. 3D conversion is best accomplished manually. This involves creating depth maps, rotoscoping ("cutting out" objects in the image), painting in missing information, and many more techniques and steps. It's very time-intensive and takes effort and experience. 3D conversion is very difficult and can almost never perfectly match "native" content that's created or captured in 3D. However, the vast majority of modern 3D movies use conversion to some extent - yes, even Avatar.

 

A 2D to 3D anaglyph conversion of a screenshot from "Mighty Morphin' Power Rangers". Converted by William3D.

 

DON'T CONVERTED 3D MOVIES SUCK?

 

3D conversion got a terrible reputation when the Clash of the Titans remake was released in April of 2010. Director Louis Leterrier had originally wanted to shoot the movie in native 3D, but this idea was shot down by the studio. After the huge success of Avatar, the studio decided to convert the finished 2D film to 3D. Leterrier had minimal involvement with the conversion and had not planned for 3D while shooting the movie. Additionally, the conversion team at Prime Focus, a company specializing in 2D to 3D conversion, was given only 10 weeks to complete the project. By all accounts, the final project was a mess; most scenes had little to no noticeable depth, nothing came out of the screen, and everyone felt cheated. Leterrier publicly decried the conversion.

 

The reputation of conversion wasn't helped by the July release of M. Night Shyamalan's The Last Airbender. Once again, the movie had been shot without any consideration for 3D, and the conversion was tacked on to the end of post-production. Shyamalan was more involved in the process than Leterrier, and more time was given to the conversion team (this time a company called Stereo D). When the project was completed, Shyamalan claimed he preferred the 3D version to the original 2D film. Still, audiences were not so enthusiastic. The marketing played up the idea that special effects would fly out of the screen at the audience, but because there had been no real planning for 3D during the shoot, this did not happen. Additionally, many viewers noted that while the backgrounds and settings were given decent depth in most scenes, the characters themselves often looked flat - like cardboard cutouts - lacking natural curvature to their bodies.

 

A converted screenshot from "The Last Airbender". Converted by me.

 

Other (but better-received and usually better scheduled) unplanned conversions of this type include Priest, The Green Hornet, Green Lantern, My Soul to Take, The Chronicles of Narnia: The Voyage of the Dawn Treader, and Thor. The upcoming release of Harry Potter and the Deathly Hallows Part 2 was also converted in this manner, though it is important to note dedication to quality seems very important to the producers, as the planned conversion of the previous film in the series was cancelled when they realized they could not produce a quality result with the given schedule.

 

However, many moviegoers were unaware that Tim Burton's Alice in Wonderland - released before Clash - was also a conversion. The effect worked much better in this case because the conversion was planned from the beginning. Burton had decided to shoot the movie with 2D cameras for budgetary and convenience reasons, but was thinking of and composing his shots for 3D. The actual conversion was also given much more thought and time than those of Airbender or Clash. The end result was a film with much more natural depth and effects that seemed to leave the screen - although some viewers did note anomalies and glitches in the conversion, most were very pleased with the experience.

 

Another movie that was shot in 2D but planned the 3D conversion in advance and took advantage of the opportunities this presented was Alexandre Aja's Piranha from August of 2010. The upcoming release of Captain America: The First Avenger is also a pre-planned conversion.

 

HOW CAN I MAKE 3D CONTENT MYSELF?

 

Get a 3D camera or learn how to make 3D conversions! If you'd like some simple help with conversions, PM me and I can let you in on the basics, plus a few tips and tricks. There are also plenty of tutorials on sites like Deviantart and stereoscopic specialty sites.

 

As for 3D cameras, there are several options. Sony's Bloggie 3D camera records in 1080p but has very, very little lens separation, meaning the 3D depth is minimal. You can get it for about $250 at retail or $220 on Amazon. There's also the HTC Evo 3D, which is a smartphone with 3D capabilities but the same lens separation issue. Prices will vary based on wireless plans and contracts.

 

My 3D camera is the Aiptek i2, which only records in 720p but has more lens separation than the HTC or Bloggie, and can be had for just $200 on Amazon. ViewSonic offers a camera that appears near-identical but costs only $97 on Amazon. I can't vouch for its quality. The best 3D camera I've had hands-on time with is the Fujifilm W3. It has great lens separation, records 1080p, is easy to operate, and costs $325 on Amazon. There are also more expensive options out there, many over $1,000. Look around and see what you like!

 

This guide is a work-in-progress and may be updated without notice!