Format wars are costly, confusing fights between consumer electronics giants battling for your hard-earned dollars. 3D got off to a slower start than hoped for, largely due to the high initial pricing, the soft economy, lack of content and pricey 3D glasses.
But now, consumer electronics manufacturers are taking sides, following a long industry tradition (remember Beta vs. VHS and HD DVD vs. Blu-ray), with the hope of increased 3D sales and market share for their respective formats.
Here’s how it breaks down.
In This Corner-Active 3D
Active 3D consists of a display that can display a separate image for the left and right eye sequentially at a rate of one frame every 120th of a second or faster. The viewer sees the 3D effect by wearing shutter glasses that sync to the appropriate frame by alternately closing off light to the left and right eyes, making the left eye see only the left eye image and the right eye see only the right.
Advantages of active shutter glasses include the ability to see the “Full HD” image 1920 x 1080 per eye produced by a source (currently Blu-ray discs and streaming). Active has excellent vertical and horizontal viewing angles, so if you stand up or move to the side, you’ll still see the 3D effect. Active shutter glasses also maintain the same vertical and horizontal resolution as the source (more on this later).
Five TV makers are solidly behind active 3D. They include Sony, Mitsubishi, Panasonic, Samsung and Sharp offering only active full resolution active 3D in 2011.
The downsides to active are that the glasses are still expensive, and they’re heavier than the glasses used with passive 3D. Both of these issues are getting better with the latest crop of glasses, but it’s likely a while before they’ll be as cheap and light as passive glasses.
The Passive 3D Corner
Passive 3D consists of inexpensive, circular-polarized glasses like the ones you get at most movie theaters. The glasses need no power source, instead they’re more like specialized sunglasses. The TV displays both the left eye and right eye image at the same time by using alternating lines of resolution. For example, of the 1080 lines of resolution that make up a 1080p screen, the odd lines 1, 3, 5 display the left eye image, while the even lines (2,4,6 etc.) produce the right side image. The screen has a special coating called a Passive Pattern Retarder. It’s this coating in conjunction with the glasses that allows each eye to see what is intended for it, and not what’s intended for the other eye. Up to recently, only one company made this filter. As it was made out of glass it very expensive and its use was limited in the US to professional monitors. LG developed a thin film they call a Film Pattern Retarder (FPR) which is much less expensive. LG also developed a process to perfectly align their FPR to an LCD screen.
With the use of passive glasses the viewer still sees the 3D effect, albeit with one half vertical resolution. So with a 1080p display, each eye is only seeing Ã‚Â 540 lines . It’s important to note that side-by-side 3D transmission, what you’d find with ESPN3D and other cable/satellite channels, is already 960×1080. So watching these channels on a passive TV will result in an effective resolution of 960×540 per eye. At one-quarter “Full HD” this is only slightly greater than DVD image resolution.
The Passive camp consists of LG, Vizio and Toshiba. Toshiba announced at the 2011 CES they will offer both active and passive 3D displays in 2011, while Vizio has completely switched over with a line of passive FPR 3D TVs with screens from 22″ to 72″.
According to published reports of a press conference at CES by LG’s Display division (we did not attend), the company will soon phase out active glasses 3D TVs. Surprisingly, LG introduced on the CES floor, multiple lines new of active 3D 2011 models including its top of the line Nano technology models.
Passive 3D Claims
LG made a number of claims regarding the superiority of its FPR 3D TVs. Based on our observations prior and during CES, some are subject to dispute. They are:
1) Active 3D TVs flicker while passive sets do not. We find this not to be the case. Flicker was not seen on production model 2010 active 3D TVs we tested or the 2011 models at CES. We only observed flicker of bright ambient light sources, such as room lamps, not the 3D TVs themselves.
2) Active 3D glasses may be hazardous to your health. LG claims having a battery close to your brain could be hazardous. This is a pretty strange claim from a company that makes millions of cell phones that not only have batteries but output radio waves as well.
3) Passive glasses eliminate crosstalk. See below.
4) Better light transmission is available with passive glasses. Passive 3D glasses typically lose 60% of the light; active glasses lose more light in large part because each eye goes black about half the time. On the other hand, there are light losses caused by the FPR in front of the LCD panel, a fact that LG fails to mention in its promotional materials. According to an industry source (see photo) the film itself and a black stripe contained within drop panel light levels by 50%. In either case, set makers can compensate by increasing the light output of the TV. In LCD this means more lamps or more LEDs. We believe this is not real issue if the set maker wants to provide a brighter 3D image, though more lamps/LEDs mean higher costs and higher power consumption.
Our research indicates a number of tradeoffs (besides one-half resolution) based on our evaluations of the first FPR 3D passive TV, the Vizio XVT3D650SV,currently for sale at Costco. Our observations took place at the CES and at a local Costco. We made all observations at the “showroom” settings as we could not access the remote control at CES and the remote control for the Costco display sample did not work.
While viewing straight on with 3D source, the FPR TV produces low crosstalk (viewing the demo material). However, one loses the 3D effect and sees significant crosstalk (double images) at just +/- 13 degrees above and below center (see graphic above). Active 3D does not have this problem; it maintains the 3D effect at various vertical viewing angles.
This could be a real issue if the display is mounted high, such as above a fireplace (which despite not being something we recommend, it remains a very popular mounting position). Conversely, if the set is on a TV table and a viewer wants to stand and not see a double image. Ã‚Â . If the seating height exceeds 13 degrees above or below the screen, a double image replaces the 3D effect. This is a major shortcoming for FPR technology.
Reduction of 3D Effect Viewing Off Horizontal Axis
We made a number of observations at a distance of about twelve feet from the 65″ display. As we moved to the right or left we began to observe the 3D effect diminish with a compression of image depth. This was noticeable at the right of left edge of the screen not very steep angle to the side. We have not seen this occur with active 3D TVs and glasses.
When watching a 3D program, one sees black horizontal lines in the picture. We could easily observe this at our twelve-foot viewing distance on the 65″ Vizio. In the early days of HDTV consumers complained about the “screen door effect” seen on 720p displays, and we ponder if the average viewer will also find this picture artifact objectionable. Imagine sitting too close to a 1080i RPTV, and you’ll have the general idea.
Reduction in 2D Image Quality Off Axis
We brought our own 2D content to the Costco store and observed a loss of contrast as we moved off to the side (see photos). Having no comparison with another similar display, we can’t rule out the cause was simply the LCD panel Vizio is using for this model. The effect is dramatic enough to warrant further observations when we can get a hold of a TV using the FPR to put through all our tests.
Regardless of claims of the superiority of passive 3D using FPR, we find the format has some very significant issues. Active glasses 3D TVs also have problems, not the least being the current price of glasses [$100-$150] which in our opinion must come down significantly for wide acceptance of 3D TVs.
At the CES we noticed a number of improvements in active 3D TV technology including brighter images, reduced crosstalk in LED LCD demos and much lighter, more comfortable glasses. HD Guru will continue to investigate both formats and report new observations.
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