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  #1  
Old 12-04-2012, 09:55 PM
Little Nemo Little Nemo is offline
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How do 3D TV's work?

I see 3D movies for sale.

I believe you need a special TV for these 3D movies, am I right? And you have to have a special set of 3D glasses?

What would happen if you played a 3D movie on a regular HDTV? Would it broadcast at all? Play a distorted picture? Switch to a default 2D setting? Open a portal to another world?

Would it make any difference if you wore a pair of those 3D glasses you get at the movies? Or are those a completely different system?
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  #2  
Old 12-04-2012, 10:02 PM
TriPolar TriPolar is offline
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On FIOS and on Cox Cable a 3D movie will appear on HD with a split screen. With the glasses you'll get each half in a different eye. I don't know what they do at the movies now, but obviously the red and blue glasses won't do you any good.
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  #3  
Old 12-04-2012, 10:29 PM
drewtwo99 drewtwo99 is offline
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You do need a special TV that will use glasses, and you also need a 3D blu-ray player as well.

If your player or device is not 3D capable, I believe there is a 2D option that will play, but perhaps it's an entirely separate disk.
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  #4  
Old 12-04-2012, 10:42 PM
FordTaurusSHO94 FordTaurusSHO94 is offline
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Isn't there 2 different kinds of 3D that you can watch at home? The one with the special glasses and 3D BD player and also the old kind that uses the fuzzy picture and the cheap glasses?
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  #5  
Old 12-05-2012, 01:37 AM
Taenia spp. Taenia spp. is offline
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While I
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  #6  
Old 12-05-2012, 02:06 AM
Student Driver Student Driver is offline
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Quote:
Originally Posted by FordTaurusSHO94 View Post
Isn't there 2 different kinds of 3D that you can watch at home? The one with the special glasses and 3D BD player and also the old kind that uses the fuzzy picture and the cheap glasses?
There are a few methods to view 3D at home.

3D Blu-Ray and a 3D monitor or projector (usually designed as a 3D TV, though converter boxes exist to use 60 Mhz or faster 2D TVs). Two types of 3D glasses are used; some sets are "passive," using circularly polarized glasses, and some sets (and current projectors and convertor boxes) are "active," using LCD shutter glasses. Passive sets have a polarization film imbedded in/on the screen, and show both eyes' frames simultaneously, interlaced. The polarization allows the glasses (which are identical to Real 3D glasses you get at the theater) to filter out the proper image for each eye. LG and Vizio are the two main brands available; with an upgrade to firmware, LG sets provide a 1080i image for each eye. Active glasses (Sony, most Samsung, projectors, as well as 3D converters) use powered glasses that are more expensive; the TV alternates between images for each eye, and the glasses flicker the lenses alternately in sync. Ideally, an active set will be 240 Mhz; this allows 120 Mhz for each eye. Slower sets will provide slower Mhz to each eye, and a viewer is pushing it by using a 60 Mhz set, only getting 30 Mhz to each eye, often with noticeable flicker.

Most 3D Blu-Rays are properly done to spec, with both images interlaced together; however, a small number use other methods (side-by-side, top-bottom) that squish both images together onto one video frame, and the TV must then convert each half of the screen into its own frame by stretching them out to fill the screen, with lower resolution. I've only run across one commercial release like this, though (an adult film from Germany), but it's common to find SBS or T/B for 3D video clips. YouTube does 3D playback, too, and you can have the YouTube player convert the video on the fly to any of the main formats or anaglyphic.

Field-sequential "active" glasses and 2D monitor. Pretty much identical to the 3D converter boxes above, but with less support. Typically used with NTSC CRT sets. FS has been around for a while (existing for VHS, VHD, DVD, and pre-3D Blu-Ray) but poorly supported, with few legitimate releases over the years which are all out of print (mostly scenery discs, with some studio support on occasion, especially the Robert Rodriguez family films). Slow and flickery, the screen alternates back and forth and the shutter glasses stay in sync. A burgeoning hobbyist scene in years past meant that a lot of unauthorized releases did exist, and it was common for 3D VHD releases from Japan (Emmanuelle 4, Jaws 3D, etc.) to get pirated here. This was also the method used by most early 3D video games-- the Famicom, Sega Master System, and the Amiga all had games and LCD glasses available.

Anaglyphic glasses and 2D color monitor. The "red/blue" glasses people still think of for 3D; each eye's image is tinted the appropriate color, then the glasses filter the images out. Most 3D releases on VHS and DVD are in this format, and before 3D Blu-Ray came out, most 3D releases in Blu-Ray were in this format (Beowulf, Hanna Montana concert). A few 3D releases on Blu-Ray are available in both anaglyphic and proper 3D: My Bloody Valentine, The Polar Express, and others.

As to whether a 3D Blu-Ray plays back in 2D, part of the 3D Blu-Ray spec requires 2D to be available on 3D releases. Some studios put both on the same disc (sometimes as separate encodes, sometimes with playback being of one eye's image only), while others package a separate 2D and 3D disc together. I have yet to purchase a proper 3D Blu-Ray that doesn't have a 2D playback mode.
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  #7  
Old 12-05-2012, 02:23 AM
Siam Sam Siam Sam is offline
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The Japanese are working on 3D TVs that don't require you to wear glasses. Not sure if any are commercially available yet. But Bangkok's Emporium shopping center put something similar up throughout the mall for advertisements a few years back. I believe it was experimental. It gave both the wife and me headaches just looking at them.
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  #8  
Old 12-05-2012, 02:30 AM
The Controvert The Controvert is offline
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Followup question: Any dopers have that new TV feature that converts 2D inputs into 3D? How well does that work?

As I understand it, software algorithms try to convert 2D images into 3D by a bunch of techniques, including: putting things near the bottom in the foreground, things at the top in the background; analyzing movement and objects, etc.

Do you frequently have to play with the settings to get a good result or is it automatic?
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  #9  
Old 12-05-2012, 08:05 AM
enomaj enomaj is offline
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2D to 3D conversion works but it's not nearly as good as native 3D. And where can I get one of those Mhz TVs Student Driver?
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  #10  
Old 12-05-2012, 08:24 AM
Student Driver Student Driver is offline
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Odd, didn't notice that I kept typing that. Guess I was more concerned with eating my lunch at the time! Hz, of course.
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  #11  
Old 12-05-2012, 08:29 AM
Kinthalis Kinthalis is online now
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Quote:
Originally Posted by enomaj View Post
2D to 3D conversion works but it's not nearly as good as native 3D. And where can I get one of those Mhz TVs Student Driver?
Screw the TV, Student Driver what was that about 3D German porn?
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  #12  
Old 12-05-2012, 08:36 AM
muldoonthief muldoonthief is offline
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Just to add one thing to Student Driver's excellent post - the active 3D glasses and TVs keep in sync by a signal output by the TV, instructing the glasses when & which eye to shutter. Up to 2011, this was an IR signal, so you needed to keep decent line of sight between the TV and glasses, but most companies have moved over to a Bluetooth signal.
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  #13  
Old 12-05-2012, 08:57 AM
Student Driver Student Driver is offline
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Following up to answer a bit more I didn't cover:

Playback of 3D movies on 2D displays: Most players (I say most because who knows what wonky cheap players might be out there) should recognize that they're not connected to a 3D set and will display the 2D version if it's a 2D/3D disc. If the versions are on separate discs, the 3D disc usually has the 2D locked out.

I have found one 3D Blu-Ray release that does not come with a 2D encode or 2D disc: Sony's Official FIFA World Cup 2010 in 3D. Apparently, 2D and 3D rights are held by separate companies.

Using glasses from movie theaters: Real3D movie glasses are compatible with LG and Vizio 3D displays, as well as upcoming Samsung passive displays. Cheap way to supplement the set at home. Dolby 3D and IMAX polarized 3D glasses are not compatible with any home displays. Never used MasterImage glasses (which are circularly polarized, similar to Real3D).

2D to 3D conversion: This earlier thread has my experience with using it.

Porn in 3D: yes, there is a bit out there. I have four titles from Germany, all softcore (16 rating); three of them are proper 3D Blu-Rays (all from Intimate Film), and work properly with any home 3D set-up. The 3D is not too bad for using prosumer cameras, but the action is a bit lame. One title from Delta Entertainment is top/bottom, and can be played on a 2D player, but requires a TV that can convert top/bottom (most can do so from a menu option, from what I've seen). American hardcore studios have released a handful of 3D Blu-Rays, and softcore 3D Blu-Rays exist in several other markets. In addition, a number of high profile porn websites offer 3D video clips which can be streamed to the TV; all I've seen are in side-by-side.
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  #14  
Old 12-05-2012, 09:23 AM
FoieGrasIsEvil FoieGrasIsEvil is offline
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So which type of home 3D TV/player system is "best"? Are any of them noticeably superior in depth of image, clarity, etc than the other(s).?
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  #15  
Old 12-05-2012, 10:37 AM
enomaj enomaj is offline
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FoieGrasIsEvil Although the Passive vs. Active debate rages on, they both look great. I was researching an LG passive but went with a Samsung active when the LG didn't drop into my price range on Black Friday. With active the TV refreshes @ 120 Hz so that alternating frames give each eye 60 Hz just like regular tv. Student Driver describes passive technology in his first post. For LG Cinema 3d, it used to mean that resolution was cut in half for each eye to 1920x540p instead of 1920x1080p. Since they've updated their algorithm, it was increased to 1920x1080i.

You'll find arguments on boards like avsforums over active vs passive or whether LG tvs are true 1080 vs. still 540 with a gimmick. The main advantages passive has over active is cheap glasses and no eye fatigue/headaches. I haven't experienced any of that but some people may. As far as 3d picture quality, I'd call it a draw.
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  #16  
Old 12-05-2012, 11:17 AM
tim-n-va tim-n-va is online now
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Does anyone make 3D glasses that are comfortable over prescrition eyeglasses?
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  #17  
Old 12-05-2012, 11:36 AM
enomaj enomaj is offline
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With passive, you can buy clip ons. My Samsung active glasses fit over my glasses and are OK. Not as bad as wearing safety glasses over prescription glasses because the arms are flexible.
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  #18  
Old 12-05-2012, 11:43 AM
FoieGrasIsEvil FoieGrasIsEvil is offline
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I so desperately want to be able to watch NFL games in 3-D. Are any of the major networks broadcasting any 3-D live television content or is everything pre-recorded/DVD/movies?
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  #19  
Old 12-05-2012, 12:53 PM
muldoonthief muldoonthief is offline
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ESPN has a 3D sports channel. No NFL yet though. I've seen college football, boxing (which is amazing), college basketball, pro tennis, and X-games - snowboarding, skateboarding and the like.

There was also a 3D channel during the Olympics.
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  #20  
Old 12-05-2012, 03:37 PM
smithsb smithsb is offline
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Quote:
Originally Posted by tim-n-va View Post
Does anyone make 3D glasses that are comfortable over prescrition eyeglasses?
http://www.projectorreviews.com/
The folks here like the Epson glasses with the newest projectors (3020, 5020, etc..). They fit over their prescription glasses.

AVSforum should have reviews/opinions on which glasses fit and how they work.
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  #21  
Old 12-05-2012, 04:25 PM
asterion asterion is offline
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I have a LG 47LW5600 3D TV. It's a passive 3D TV, which means that, as mentioned earlier, the glasses are a heck of a lot cheaper and they work with some 3D movies in theaters. Even better, you can get clip-ons that work with both the TV and at the movies, which is much more comfortable. My 3D source is a Playstation 3, and I mostly use it for 3D gaming, although I have bought a couple 3D BluRays. I used to pay TimeWarner Cable for the 3D tier when they were promising that they'd get more material. I stopped because I was paying $11 a month for ESPN3D and only ESPN, and there wasn't enough programming to justify it. The 3D channel for the Olympics was free, but again, the coverage was hit-or-miss. On the plus side, it was the feed from the BBC, so it was much more pleasant than most of NBC's coverage.

3D gaming can be really fun although it takes some getting used to.
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  #22  
Old 12-05-2012, 05:23 PM
Student Driver Student Driver is offline
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Originally Posted by enomaj View Post
FoieGrasIsEvilWith active the TV refreshes @ 120 Hz so that alternating frames give each eye 60 Hz just like regular tv. Student Driver describes passive technology in his first post. For LG Cinema 3d, it used to mean that resolution was cut in half for each eye to 1920x540p instead of 1920x1080p. Since they've updated their algorithm, it was increased to 1920x1080i.
There are 240 and 480 Hz active sets, too, so the "downgrade" for each eye would be 120 and 240Hz respectively.

I went with passive (LG) due to lower overall barrier to entry at relatively low trade-off in quality. Unless you get a deal with active to get glasses bundled in, you generally have to pony up an extra $100 to get your first set of glasses, and buy more glasses for additional viewers. For passive, the glasses are practically free (I've had to tell friends to stop giving me their theatrical glasses). In addition, I wanted 120 Hz or higher for each eye (noticeable when gaming, watching sports, and fast action), which would have necessitated looking at more expensive 240 Hz active sets, but was able to stick with 120 Hz for passive.

The downgrades in quality I made: passive sets have a more strict angle of viewing, requiring viewers to be close to center. Not ideal for large viewing groups, or set-ups where the TV must be at an angle from the viewer. In addition, there is the 1080i vs. 1080p issue; I found the effect to not be noticeable. However, I did see a noticeable drop in resolution with the original 540p algorithm; if the firmware had not updated, I'd have gone with active. Not sure what methods Vizio or Samsung use on their passive sets.
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  #23  
Old 12-05-2012, 08:24 PM
Siam Sam Siam Sam is offline
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Quote:
Originally Posted by tim-n-va View Post
Does anyone make 3D glasses that are comfortable over prescrition eyeglasses?
I don't know if they're commercially sold, but the one or two times the wife and I tried out 3D in the cinema, the 3D glasses fit comfortably over our pescription specs. So they are out there.

Last edited by Siam Sam; 12-05-2012 at 08:24 PM..
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  #24  
Old 12-06-2012, 03:13 PM
Chronos Chronos is online now
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There's been some mention of screens that work without the need for glasses. These all work on the lenticular principle: There's a ridged cover over the screen that throws the different images in different directions. You've probably played with toys that show a different image from different angles: This is the same idea, just made higher-quality. The advantage, of course, is that you don't need any glasses. The disadvantage, though, is that you can't move your head much, or you start seeing the right-eye image in your left eye, and/or vice versa.
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  #25  
Old 12-06-2012, 07:54 PM
Student Driver Student Driver is offline
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Originally Posted by Chronos View Post
There's been some mention of screens that work without the need for glasses. These all work on the lenticular principle: There's a ridged cover over the screen that throws the different images in different directions. You've probably played with toys that show a different image from different angles: This is the same idea, just made higher-quality. The advantage, of course, is that you don't need any glasses. The disadvantage, though, is that you can't move your head much, or you start seeing the right-eye image in your left eye, and/or vice versa.
I imagined this would be the case. Restricted view angle is one of the downsides of passive sets that use glasses, and sounds like it's going to be a downside of any passive set.
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  #26  
Old 12-06-2012, 08:50 PM
Chipacabra Chipacabra is offline
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Originally Posted by Chronos View Post
There's been some mention of screens that work without the need for glasses. These all work on the lenticular principle: There's a ridged cover over the screen that throws the different images in different directions. You've probably played with toys that show a different image from different angles: This is the same idea, just made higher-quality. The advantage, of course, is that you don't need any glasses. The disadvantage, though, is that you can't move your head much, or you start seeing the right-eye image in your left eye, and/or vice versa.
This is how the nintendo 3DS works. Since it's a handhold game console and, by its very nature only has one person viewing it at a time, it works really well.

Also, with the advent of head tracking, there are parallax tricks that you can do even with a traditional 2D screen that are very convincing. The human brain uses a bunch of visual cues to create a 3D image, and stereoscopic vision is only one of the tricks. On the other hand, head tracking doesn't work very well with more than one viewer!
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