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My only hope is for glasses free 3D.
It's been tested but not ready for mainstream I guess.
I've got a UHDTV that does 3D.
Haven't even unpacked the glasses.
Don't plan to.

tigerfan33 said:

My only hope is for glasses free 3D.
It's been tested but not ready for mainstream I guess.
I've got a UHDTV that does 3D.
Haven't even unpacked the glasses.
Don't plan to.

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I've read that glasses-free 3D is the same as passive, which cuts the vertical resolution in half. So it'd be only 1080p 3D. I'd rather get an active 4K or 8K or whatever and get 3D at the full resolution of whatever the resolution is. I wouldn't want any resolution degraded.

edisonprime said:

I've read that glasses-free 3D is the same as passive, which cuts the vertical resolution in half. So it'd be only 1080p 3D. I'd rather get an active 4K or 8K or whatever and get 3D at the full resolution of whatever the resolution is. I wouldn't want any resolution degraded.

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The glasses free panels do reduce the 4K resolution visually, but I wouldn't go as far as to quantify it. The specs are just not yet published. What happens is these companies are using a 4K TV and modifying it so the picture processing and display is 4K but what comes through to your eyes is obviously lower, especially if you put them next to a passive 4K panel with 3D display.

Krell said: Plus IMHO again, you need 4K to do adequate resolution 3D using passive glasses. (Correct me if I'm wrong, but I believe passive halves the resolution of the set, hence the need for 4K.)

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The debate over passive panels reducing the vertical resolution to 50% is not exactly correct. While Samsung claims passive does cut the vertical resolution while their active panels offers full 1080p ( 2160p for 4K sets) vs. LG who claim there is no reduction and the vertical is still 1080P (2160p for 4K sets.)
Here is the explanation and why the controversy:

(Numbers for a 2K TV):

In a passive set the picture is displayed as 2 images overlapped 1080p x 1920 left and right eye. The film pattern retarder ( FPR ) on the screen surface will filter half the image in a line slicing pattern so that there are only 540 lines for the left and 540 for the right for each frame. But when you put on your polarized glasses the 3D image overlap fills in so that the image converges in your brain to a full 1080 x 1920. A 2D image will be missing the right eye so with polarized glasses the screen will have only one 540p image visible and a fine set of horizontal black lines becomes visible. Of course you wouldn't watch a 2D program with polar glasses would you? So the truth is, a passive TV still offers a full 1080p 3D vertical resolution. In effect, nothing is lost.

In an active TV, we still display the two 1080p x 1920 images on the screen at the same time, but to build the 3D effect, as you know, the active glasses sync with the tv and the left and right eye alternate fast enough so your brain combines them as one 3D image. The resolution is still 1080 x 1920. Some claim that active 3D TV's causes them headaches. It is my opinion that active TV's with lower refresh rates such as the older 60 Hz and 120 Hz had more problems with this than today's 240 Hz active screens. The faster the switching between left and right eye the less chance your brain will see the switching and manifest it in a headache.

More likely, headaches with all 3D are caused by extreme ranges of negative and positive parallax which makes your eye muscles strain to converge the 3D ( to avoid the double images ) For example, when an object real or illusion as in stereoscopic 3D, is very close to you in front of your screen, your eyes will cross and this works the eyeball muscles. When an object is way behind the screen your eyes have to diverge ( a Marty Feldman eyes ) to keep it in view as 3D. Now when both are on at the same time, your vision really has to work hard and all this eyeball muscle work causes eye fatigue and headaches. Therefore the 3D design of the program can and probably is the real culprit of eye strain and headaches. The reason for this is that most people are not satisfied with subtle 3D entertainment. They want extreme "pop out" and that extreme over a couple hours movie can cause severe eye strain.

What claim the active panel TV makers can legitimately make is that their sets offer 1080 x 1920 to each eye, but you only see each eye separately and 50% of the time it is shut down or blacked out by the glasses. The Passive TV makers can claim that their sets offer 1080 x 1920 all the time because the 3D picture is constructed of both left and right eye images that are 540 x 1920 each. Then the combined resolution in your brain sees is 540+540 x 1920 pixels per frame.

Bottom line is that 4K passive doesn't get reduced to 2K for 3D. It will still be a full 4K image. ( 2160p x 3840 ) In addition, the 4K not only increases your pixel resolution but also adds additional color gamut and depth offering higher number of colors to reduce banding and posterizing artifacts on the bigger screens.


So, what 3D does get halved in 3D resolution? There is a format used by many 3D distribution systems such as YouTube where the video is actually a 2D 1080 x 1920 image that is cut in half where the left half is left eye and right half is right eye. This is called side by side half, or SBSh. There also is an over under format that also suffers a loss of resolution. SBSh allows transmission compatibility with 2D transmission but you still need a 3D TV placed in SBSh mode to view it. Blu Ray disks do not use SBSh. They use a very special and complex coding called MVC or multi view coding where we have a dependent view and an independent view. The dependent file is used to calculate the right eye image from the independent view or left eye file. The decoder in your blu ray player will recreate the 3D for the TV to display. How this is done is beyond this post. but it's like a method of file compression.

Don Landis said:

In a passive set the picture is displayed as 2 images overlapped 1080p x 1920 left and right eye. The film pattern retarder ( FPR ) on the screen surface will filter half the image in a line slicing pattern so that there are only 540 lines for the left and 540 for the right for each frame. But when you put on your polarized glasses the 3D image overlap fills in so that the image converges in your brain to a full 1080 x 1920. A 2D image will be missing the right eye so with polarized glasses the screen will have only one 540p image visible and a fine set of horizontal black lines becomes visible. Of course you wouldn't watch a 2D program with polar glasses would you? So the truth is, a passive TV still offers a full 1080p 3D vertical resolution. In effect, nothing is lost.

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So it's OK to sum the 540 line resolution in each eye, as perceived by my brain, and call it 1080? By that reasoning, I should be able to claim that, because my brain blends 24fps into continuous motion, we should just call it "continuous" and be done with frame rate. And here I thought that TV specs were confined to the TV, and not my perception.

I now own two 3D capable Samsungs, one 1080P and one 4K. Each came with four pair of glasses. All still remain in their original wrapping in the box they came in. I doubt I will ever use them. I wonder how many more like me are out there? You cannot buy a higher end set without being 3D equipped.

Never mind crossed eyes or Marty Feldman eyes, let's discuss Bette Davis eyes.

TheKrell said:

So it's OK to sum the 540 line resolution in each eye, as perceived by my brain, and call it 1080? By that reasoning, I should be able to claim that, because my brain blends 24fps into continuous motion, we should just call it "continuous" and be done with frame rate. And here I thought that TV specs were confined to the TV, and not my perception.

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There is quite a bit of converging of the physical senses and the TV or film motion to create the illusion of motion. The resolution of the motion has been reduced to some rather complex math in the academic texts on film and TV, much abbreviated in the Society of Motion Picture and Television Engineers Handbook.
Perceived motion can begin with a noticeable bit of jerkiness at about 10 frames per second. Computer video in the late 80's ran at 15 fps as a standard. Old 8mm film ran on low speed of 18 fps. Traditional motion picture film is 24 fps. When TV was invented using analog technology there was a compromise of design and it was settled in on 60 frames per second but the bandwidth was too high and the picture tubes phosphors were too slow back then to display properly without a lag of a ghost image, several of them for several seconds before complete phosphorescence decay! The invention of interlaced video resolved this as it lowered the fps to 30 divided into two fields with half vertical resolution per field. The first field remained on the screen long enough to blend with the second field to produce one whole frame. But the alternating retrace could "erase" the phosphor glow while the other field supplied picture. Progressive scanning just didn't perform well as interlace on phospor tubes unless for still images. Not only did this preserve the original resolution, it smoothed out the image motion resolution far better than film at 24 fps. Hollywood, fought the TV technology by claiming 24 fps was an art form that gave some mystical surreal life to the movies that TV could not produce. Next we have color entering the picture and this added to the complexity of the display but the frame rates and bandwidths and final resolution remained. Then along comes Digital TV and now everything changes. Broadcast Digital TV is still quite limited due to bandwidth limitations as well as backward compatibility issues but non broadcast TV such as internet and media distribution has a wide open playing field. Here we can increase the frame rates for even smoother 1080p ( full frame ) at 60 fps. and double that vertical resolution to even higher 2160p. In addition, new display systems have much faster switching so that an image can be refreshed as fast as 480 Hz, but the top end of most commercial TV's are sold at 240 Hz improving the motion resolution even more. While the frame rate may remain at 60 top end for bandwidth, the picture may be updated on the screen 4 times for each frame. As most TV is really only 30 fps, the image is updated 8 times per frame. This produces an even sharper reproduction of the motion than the old days when we had a refresh rate of 60 Hz and the image was only updated 2 times per frame. Net result is less motion blur.
Now, having said that you should know that most Blu ray 3D and 2D disks sold are movies that were originated at 24 fps. Therefore the Blu Ray Disk Association standardized their format to 1080 24p not 1080 30p. The movie industry held tradition and forced the standard to 24 fps in the interest of the art. But we now gain a motion sharpness increase by refreshing each image on the screen 10 times in a 240 Hz refresh rate HDTV. The difference between 8 and 10 times vs having a 60 frame times 4 is hardly noticeable so we may have reached the physical senses limitation on this end, especially at HD resolution. For UHD of 2160p we get to start the debate all over for now we want to preserve the motion sharpness with a lot more pixels so the story may change and 240Hz may not be adequate. I've been hearing that 8K TV's will need 960 Hz refresh rate to preserve the motion sharpness on an 8K screen.

On the non geek speak, what you see on a HDTV with low refresh rate vs high is a still picture that is very sharp, but when there is motion it blurs out to a lower resolution. High frame rate source ( 60p), yields a smoother motion, and high refresh rate holds the sharpness of the set's still image quality when there is motion.

The next question is at what size screen do we have to have to justify the UHD or 8K TV's? Many of the smaller displays for 8K are 100"+ in size and it is hard to see the difference when next to a 4K on a 70" At some point these super high definition systems will only be offered in screen sizes best used in large rooms or commercial applications. I would say we reached our practical limit at 4K for home viewing in most homes including home theaters.


There is a whole separate discussion on color depth that is becoming a key factor too, especially as we go to bigger screen size. How many colors can the eye perceive? Trust me, it's far more than one's vocabulary.

klang said:

I now own two 3D capable Samsungs, one 1080P and one 4K. Each came with four pair of glasses. All still remain in their original wrapping in the box they came in. I doubt I will ever use them. I wonder how many more like me are out there? You cannot buy a higher end set without being 3D equipped.

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So true as 3D has become a staple like stereo sound in all high end TV sets. It's not mandated yet but might be one day by the FCC on certain class TV's like.

But that doesn't mean you must use the feature. How many own a TV with a UHF tuner and don't put up a UHF antenna?

I have a high end Ford Escape. It came with a feature called auto park. Push the button and it parks your car. I haven't used it since we tested it on the dealers lot the day I picked it up.