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Should You Wait for Passive 3DTVs?
Oakley, the company best known for high quality sunglasses was in the news recently with an announcement of their new circular polarized “passive” 3D glasses called 3D Gascans. These glasses can be used to watch movies that use the RealD (polarized) format which is currently only available in movie theaters. However, soon you might be able to use these and other "passive" glasses to watch 3DTV at home when 3DTVs that feature passive 3D technology become available from companies like Vizio and LG.
3D Glasses Format War?
Just when we thought everyone was going to play nice and move forward with one standard for 3DTV glasses in the home, we start to see a division growing between LG and Samsung the two largest LCD panel manufacturers in the world. Samsung, Sony and others have settled on active shutter glasses while LG and Vizio are about to introduce 3DTVs that use passive glasses. Nvidia, which offers 3D technology for things like 3D computer gaming has also indicated a preference for active shutter glasses.
Is There A Difference in the 3D Experience?
Active shutter glasses use an IR beam from the TV to synchronize LCD shutters in the glasses which trick the brain into thinking it’s seeing one 3D image from two alternating frames. Passive glasses, like the ones from RealD that are commonly used in movie theaters use circular polarizing filters to send different images to each eye. Dolby 3D glasses, also commonly used in theaters use a different "passive" technique. Active glasses require batteries and typically cost over $100 a pair. Passive glasses are much cheaper, lighter and don’t require batteries.

Passive 3DTV sets like those coming from Vizio and LG require a micro-polarizing filter precisely embedded in the screen so the TV can send every other line of the 1080 lines to each eye. Because of this each eye only gets 540 lines or half the pixels of a full, 1080 frame. The added polarizer filter could also add cost to the TV, at least, at first.

Most distributors of 3D programming like cable and satellite companies take a full 1920 x 1080 (HD) resolution feed and use one of several techniques to reduce the bandwidth requirements which allows them to use existing bandwidth to distribute 3D programming.


Two common techniques are side-by-side that removes half the horizontal pixels leaving 960 pixels per frame and over-under that removes half the vertical lines resulting in 540 lines for each eye. Typically, 3DTVs using active shutter glasses take the half-resolution frames, add the missing pixels through a technique like interpolation and display alternating, full HD resolution frames at high frame rates. Passive TVs will add the missing horizontal pixels if necessary but will still show only half the vertical pixels.

Whenever you remove half the pixels that originally came from the 3D camera you're going to lose some image quality even though you do get some of those pixels back through pixel-adding interpolation. Blu-ray distributed 3D material delivers the most 3D pixels but even with passive 3DTVs you're still going to lose half the vertical resolution from a 3D Blu-ray movie because it's only going to show 540 lines to each eye. To be fair, some experts maintain that your brain will compensate for the missing pixels and you'll never notice any difference. On the other hand, when you sacrifice 50% of the pixels, brightness may be reduced. Fortunately LCD TVs can generate a lot of light to compensate for some of that loss.

Cost, Interoperability
and Practicality

Despite the fact that Oakley is charging over $100 for their Gascan glasses, passive glasses will most likely cost well below $50. You should even be able to put them in a dishwasher just like the movie theaters. Cheaper glasses mean less cost to equip a family or group of viewers and it would be much less costly when someone accidentally sits on a pair of them which you know is going to happen to you 3D glasses sooner or later. The other advantage is they should all work with any RealD-powered 3DTV set or movie theater. The trade off may be in a higher priced passive 3DTV set however, maybe Vizio (known for competitively-priced TVs) can deliver a low priced, passive set out of the gate.

Interoperability has been an issue with active shutter glasses. There is no standard that manufacturers have agreed on that would make one pair of active shutter glasses work with any active shutter TV. The Consumer Electronics Association (CEA) has said they are addressing this issue and hope to have a standard in place before too long. Meanwhile a company named XPAND announced its Universal X103 3D glasses ($129 on Amazon) that can work with a long list of 3DTVs.

Bottom Line
We haven't seen passive 3DTV with our own eyes but we are curious to see how the half resolution of 3D images compare to the full resolution possible with active shutter (from a full 3D HD source). Needless to say passive glasses have a lot of practical advantages over active shutter glasses but it remains to be seen which ones offer the superior experience. We'll also be watching to see if Dolby's passive technology makes it into 3DTV sets any time soon. Dolby could represent a third standard for 3D glasses in the home.
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Thanks

Thanks

The right way to do HD 3D

I believe the only right way to do 3d HD is with 2 full size videos. HDMI has the capacity for this.

Active shutter glasses are out of the question!

Either use 2 front projectors aligned perfectly (preferably built into 1 unit). Or use a rear projection dlp at 240Hz with it flipping polarity every other frame (or use 2 dlps in one set).

LCD can't do this, but for projectors, the WHOLE surface area will be available to each eye!

3DTV

Gosh boys 7 girls, I still like the black & white westerns from the 1930's and 40's.

The article missed some of

The article missed some of the benefits of the passive glasses and miss stated (I am guessing they haven't actually used them yet??) others. I have seen numorous demo's of both technologies for both consumer and commercial applications and I can't see any justification for the active glasses other than as a revenue stream (the manufacturers will tell you that the incremental cost of either technology in the display is negligible).
Unlike the shutter glasses, which not only cut the overall brightness (well, if your eye is covered half the time, things will appear dimmer right?), but also often get off sync, so that one eye, or both, will seem to vary in brightness, the passive glasses maintain consistant brightness, and don't cut overall brightness at all (since both eyes are exposed to the brightness of the screen 100% of the time).
The active glasses also have a very limited viewing cone, so you can't get very far off axis before they lose sync and start 'dimming' your view randomly. They also can't be tilted, so don't try to use them laying on the couch!
Overall 3D on a small screen (one that doesn't significantly fill your field of view) is really more a marketing push than a real advancement in technology. The only real benefit on the small screen is seen on the little bit of programming material that uses 3D to enhance depth of field, although the already artificial depth of field provided by HD cinimatographers using infinite focus, and the nature of LCD TV's to look 'deep' (due to different color pixels being located at different depths in the substrate) already give many viewer fatigue, so adding in bulky glasses seems to be a waste of time and money!

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75 percent of the population

75 percent of the population need eye correction and many of those wear glasses. Having polarized clip ons with a passive system is far superior to wear glasses over glasses as would be needed by the active system

No more 3D glasses.

3D technology is definitely a cool step in home entertainment but darn when are we gonna retire those glasses! :)

3d tv without glasses

hi,
i spoke to someone at best buy and did research via google and they are coming out with 3d tv's which you don't need anything like glasses to see the piture in 3d. it is coming out winter 2011.

Seriously???

That is just hilarious, that you really believe a Best Buy employee knows what is coming out Winter of 2011. Think about it, a 3D TV without glasses is almost hologram technology. There have been displays shown at the CES show in Las Vegas for the last 2 years that don't use glasses but they are of a lenticular design that has about 7-9 "fields of view" (image is clear...take a step to your left or right...image is blurry...and so on). Also, the resolution is very pixelated. Granted the 3D effect is very cool, but even these displays are geared more for commercial advertising since image quality is nowhere near HD or FullHD for that matter. Best Buy employee...you crack me up man!

3D (or Beat vs VHS or whatever)

This is exactly why I haven't bought my 3D set yet. I know I am missing out on the wonderful feeling of 3D movies and shows. However, I am getting tired of getting stuck with equipment that is either not supported, obsolete, and/or not even content.

You wouldn't take this if it was the automobile industry! Can you image getting a car that controls itself but after 1 year the company decided to abandon the idea for a different feature.

No thank you. I will continue watching my 3D movies at the theater for now. I will hold out for the true 3D - a Holodeck like in STAR-TREK.

It seems to me

Why can't they have a polarizing filter that can switch polarization depending on a voltage or current? In that way there would be a switching TV screen & not a set of glasses. Then we just need a twice as fast refresh rate to handle the 3D as is done with the switching glasses.

I wear glasses so having a set of bulky switching glasses on top of my vision glasses is simply NOT going to happen. They just have to come out with clip on LEFT/RIGHT circularly polarized "sun" glasses for me to clip on. That's a MUCH better option. Oh, and the bottom line cost of such things should be less than $10, and I DON'T mean $9.95! There is no reason, other than getting their hands in our pockets, that these glasses have to cost even $50.

Still, I may simply wait till they come out with a no glasses needed 3D set. They won't transmit the image then, they will transmit the wave front, just as a hologram records the wave front. Unless there's a simpler way, which, there probably is.

Buck Rogers

I remember the quality of those glasses too, I had to hold them on my head for half the movie and everything was green and red, although it was an amazing experience afterwards until your eyes adjusted.. lol

3-D TV

I still remember when we used to get 3-D glasses free in a box of Froot Loops to watch 3-D movies. Those did not go very far, I do not see why expensive TV's with expensive 3-D glasses should go anywhere. I can see it now, the whole family and friends sitting around the TV with their "Special" Buck-Rogers glasses watching TV and munching on Cheetos. Get off your tails and go & visit the Andes, or Egypt, then you will see them in real 3-D.