HardwareZone's 3D TV Buying Guide Essentials

Stereoscopic Televisions: Past & Present

Visual depth. That's what today's televisions offer as opposed to their "flat" 2D counterparts. And it didn't seem too long ago either when 3D TVs went mainstream. In reality, it's been almost three years since the first consumer 3D TV was announced. It is debatable, but Hyundai's 46-inch E465S may well be the first 3D screen to land in the consumer space. Since then, 3D televisions have evolved into variants with differing technologies, such as alternate-sequencing (or active-shutter) and polarized forms we see in electronics stores today. Such variety can mean two things - more options for the consumer, but on the contrary, it also hinders standardization efforts with regards to the unification of 3D display technology.

According to sentiments gathered from industry insiders, the current fleet of 3D televisions will find it hard to establish a niche in the consumer market due to their eyewear dependency. To answer that call, Toshiba came up with 12-inch and 20-inch lenticular models back in 2010. By implementing a parallax-barrier approach, both Regza models enabled a user to experience 3D visuals without the need for glasses. Sadly, they failed to take off in terms of sales numbers, due to their tiny screen estate, steep price tags and tight viewing angles. The 20-inch GL1 demanded US$2,900 when it was first launched. Today, 3D TVs are mostly a mix of active-shutter types plus the newly introduced passive flavor by LG. There's more on these in the following pages (you can use the jumps below). If you are keen on purchasing one, then step right in and help yourself further to our buying guide. Ultimately, only YOU can decide if 3D is worth paying the extra premium for.

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(Recommended Read: If you need a primer on HDTV (the various display technologies and market trends), and things to look out for when buying one, do also check out our HDTV Buying Guide.)

How Do 3D Televisions Work?

Before we begin, let's take a closer look at the dynamics of a 3D TV. Stereoscopy, or 3D imaging, does not entail rocket science, but it calls for a bit of cunning and trickery in order to fool your brain into seeing a 3D picture. Fundamentally, stereoscopic images appear blurred when viewed with naked eyes. That's because the display is sending two sets of images, one for the left and the other for the right eye. When applied with the right type of eyewear (depending on the 3D technology used), these two images are combined by the brain which then interprets them as a single image with depth. These left and right images are typically shot on cameras with discrete lenses, spaced marginally apart to create a slightly different perspective. Alternatively, a conventional 2D film can be post-processed to create left and right eye pictures.      

In the past, flatscreen displays did not make suitable candidates for 3D due to their slower frame rates. For example, a 50Hz TV can only yield 25 frames per second (for each eye) at best. It is unlikely anyone would enjoy flickering 3D images, would they? Thankfully, the AV landscape has evolved dramatically since then. With native 100Hz or 120Hz frame rates (do not confuse this with pixel response time) being a reality now, manufacturers are empowered to develop functional 3D screens for the consumer end. As we speak, however, TV makers are still in the process of tweaking their offerings to bring the stereoscopic experience one step closer to perfection.

3D Formats: Frame Packing vs. Top-and-Bottom vs. Side-by-Side

Not all the 3D content are the same; some come from original 3D sources, some are recreated from 2D. For most consumers, the best 3D content will be those from Blu-ray Discs. Typically encoded at 1080/24p, they employ a method called frame packing, which in layman's terms, is the stacking of two 1,920 x 1,080 images (with some spacing in between) one atop the other. (This creates a tall 2,205 x 1,920 image that you don't actually see.) The 3D image quality is high simply because each eye gets a full HD image.

Due to bandwidth concerns, frame packing is not favored for cable and over-the-air 3D content. In fact, most broadcasters stick to 1080i in order to strike a balance between the need to offer their viewers HD quality content and the need to increase the number of HD channels or streams. In most of these cases, they will try to have the two images needed for each eye be merged into a single image. There are two main ways of doing this: top-and-bottom and side-by-side.

As the name implies, the top-and-bottom method uses either two 1,280 x 360 (for 3D in 720p) or two 1,920 x 540 (for 3D at 1080/24p) images, one on top of the other. The side-by-side method is similar, just that it's now the horizontal (instead of vertical) resolution that's halved. In other words, each eye will get either a 640 x 720 or a 960 x 1,080 image. While some may say that the top-and-bottom method is better for sports content, at the end of the day, neither offers very high image fidelity due to the often noticeable drop in resolution.

Understanding 3D TVs

For those who are less acquainted with home theater offerings in general, we can imagine how perplexing it is to experience the bevy of 3D televisions out there. Whatever happened to the days when TVs were all alike? Why are there different types of glasses accompanying these 3D screens? Can this TV work with other brands' AV equipment? If you find yourself asking similar questions along the way, then this guide is for you. Let us begin by providing you with a little insight on the two major 3D technology before we touch on the various pros and cons of owning a 3D set.  

The Active 3D Faction

Essentially, a large majority of so-called active 3D televisions utilize the alternate-frame sequencing methodology. In other words, the TV's onscreen images are transmitted to the viewer in alternate sequences. For example, a dedicate frame is designated for the left eye, while the subsequent frame is meant for the right eye. For this to work, active-shutter glasses are required to be worn by the user. These lenses are filled with liquid crystals which turn dark when a voltage is applied. For instance, the left lens is darkened when the right picture frame reaches the right eye, and vice versa for the left eye. These glasses also contain a receiver, which works in tandem with the TV's emitter to coordinate the shuttering lenses with the alternating frames. Each lens shutters on and off at about 50 or 60 times a second, which also explains why an active 3D TV needs to have a minimum of 120Hz (2 x 60Hz) refresh rate. Sony, Samsung and Panasonic are some of the main players in this group.

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The Passive 3D Camp

Unveiled this year, LG's passive Cinema 3D series is undoubtedly the biggest competitor to the active 3D TV troops since its inception. Based on its FPR (Film Patterned Retarder) technology, LG's latest suite of Cinema 3D televisions involve a special circular polarizing film applied unto the panel, designed to transmit simultaneous left and right eye images to the viewer. A pair of polarized lenses then filters the images accordingly. While this process may sound similar to their active-shutter rival, both technologies are actually quite different in the way a 3D picture is transmitted to the viewer.

Instead of transmitting one frame for each eye, a single frame is shared between both eyes. In other words, interlaced within each frame are left and right eye fields.This effectively halves the resolution for each eye as well, and also results in a "CRT effect" when viewed up close due to the visible horizontal lines. So how do the Cinema 3D televisions create a stereoscopic effect? To put it simply, each of these left and right eye fields actually consists of segmented odd and even "scans" respectively (see diagram below). The job of the polarized glasses, on the other hand, is to filter these scans such that the left eye only sees the left lines, and vice versa for the right eye. The brain then combines both fields to form a stereoscopic image.

Comparing Both 3D TV Technologies

Still undecided on which 3D tech is the most appropriate choice? Worry not, for here is a summary on the various strengths and weaknesses of the active-shutter and passive factions. However, we'd like to remind you that the 3D viewing experience can be subjective, and it's really up to you to draw the final conclusion as to which technology works best for you.

Active 3D Televisions	Passive 3D Televisions
Dedicated 1080 lines of resolution for each eye. In other words, each of the left and right eye obtains a full HD 3D picture	3D resolution is halved. For example, only 540 lines are transmitted to each eye simultaneously
Absence of horizontal "scan" lines when viewed at any distance	Horizontal lines are evident, especially when viewed up close
Better image and edge detailing	Softer edges due to the "CRT effect"
Slightly wider vertical viewing angle	Narrow vertical viewing angle

Essentially, you might want to consider an active 3D TV if you're fastidious about picture quality such as finer detailing. Active types are also suitable if you are planning to install the TV in a location where your eye-line isn't on the same plane as the display. For instance, when the TV is much higher than your eye level when seated. While active-shutter 3D televisions are more affordable these days, their accompanying eyewear could cost you a hundred dollars or more. On top of that, those flickering annoyances under fluorescent lighting may also serve as deal breakers for some eventually.  

  

Passive 3D Televisions	Active-shutter 3D Televisions
Doesn't suffer from flickering issues when viewed under fluorescent lighting	Flickering is apparent under fluorescent lighting conditions
Minimal crosstalk	Intermittent crosstalk
Lesser eye-strain	Viewers are susceptible to eye fatigue
Glasses are lighter and less expensive	Eyewear is significantly more costly than polarized types
Uses polarized lenses	Active lenses require power (or batteries)

To be honest, there are more pros than cons with regards to the passive camp. Take LG's Cinema 3D (FPR) series, for example. They use lightweight, power-free, and affordable glasses. On top of that, users also suffer less from eye fatigue and flickering issues for the most part. Crosstalk is reduced as well, assuming the viewer is seated centrally in front of the screen. On the flip side, passive screens have relatively tight vertical viewing angles. And the "shared" fields for both eyes might discourage AV enthusiasts concerned about the TV's 3D high-def quality and intricate picture details.

Seven Deadly Myths About 3D Televisions

Myth #1: I need to wear 3D glasses at all times while viewing a 3D TV.

The answer is 'yes' for watching 3D movies or programs, and 'no' for conventional 2D shows. Almost every 3D TV model in the market is able to display images in 2D or 3D mode. Some sets are able to convert 2D sources to 3D as well. Glasses (regardless of active or passive types) are only required for viewing 3D content.

Myth #2: All 3D HDTVs can display 2D content in 3D.

Again, this isn't entirely correct. While many premium models like Panasonic's V series and Samsung's Series 8 are capable of converting 2D signals to 3D on the fly, some of the mid-range models are only able to display content strictly in 2D or 3D mode without any conversion features.

Myth #3: My 3D TV is only compatible with 3D Blu-ray players of the same brand.

Active and passive 3D displays are compatible with most brands' Blu-ray players, as long as the BD players themselves are 3D-capable. There shouldn't be an issue as long as the Blu-ray deck is capable of decoding the MPEG4-MVC (Multiview Video Coding) format used by 3D Blu-ray discs. 

Myth #4: All active shutter glasses are the same, and they can be used with any 3D TVs.

This is incorrect. Reason being that active-shutter glasses are based on IR (infrared) or RF (radio frequency) protocols, while others are using Bluetooth technology (like some of Samsung's recent 3D eyewear). It's best to use the brand's recommended glasses.

Myth #5: All Blu-ray players equipped with HDMI 1.3 can be upgraded to 3D BD players. 

Apart from the Sony PlayStation 3, the HDMI standard is determined by hardware components and cannot be upgraded by a simple firmware upgrade. You'll need an entirely new chip for HDMI 1.4.

 

Myth #6: There is no disparity between 3D-ready and Full 3D televisions.

Both 3D-ready and Full 3D operate in a similar fashion. And they also utilize the same alternate frame sequencing technology and the use of active-shutter glasses. However, there are some older 3D-ready models which require an external IR syncing transmitter. On the other hand, Full 3D TV sets typically come with integrated transmitters.  

Myth #7: Crosstalk is associated only with LCD panels. 

Crosstalk or ghosting happens when shutter lenses fail to block light from entering the respective eye when it isn't supposed to. Alternatively, an LCD panel's slower pixel response time also leads to crosstalk. In other words, "double images" may appear when the pixels take longer to change their display state. Current LCD panels have an average response time ranging from 2 to 4 milliseconds.



Plasma displays are better off in that they have a faster (0.001ms) response time. However, PDPs aren't totally free of crosstalk, since the "phosphor-lag" phenomenon may produce crosstalk effects too. Recent models such as Panasonic's V-series with their rapid decay time phosphors can help mitigate this.

A Complete 3D Home Theater Setup

We've established that a 3D-capable TV is required for a 3D Home Theater setup. Fair enough. But what about the rest of the AV components? Will your current Blu-ray player suffice? Can you still rely on that cranky old AV receiver for 3D sources? What about VOD content? Will you require any additional equipment in order to stream 3D movies to your TV? Here are some of the recommended AV components to complete your 3D home cinema experience. 

Getting to Know the Rest of the 3D AV Crew

To be honest, creating a 3D "ecosystem" at home takes much more than a 3D telly. In other words, a 3D display is effectively useless without an appropriate 3D source. That is, not unless you can live with 2D to 3D converted pictures on your TV all the time. To get you started, here are some AV components for your consideration before you lay your money down.

3D Blu-ray Player

You'll need a 3D Blu-ray player equipped with the latest HDMI 1.4 standard and Blu-ray 3D support. The older HDMI 1.3 version is unable to transport dual 1080p streams as reproduced by 3D BD sources. This applies to BD drives manufactured before 2009 mainly. The recent Philips BDP9600 (shown above) is armed with HDMI 1.4 and features a TI Burr-Brown DAC as well.

3D Blu-ray Discs

The majority of 3D Blu-ray movies are encoded using the MPEG-4 MVC format with dual 1080p streams on a typical 50GB Blu-ray disc. More importantly, these 3D titles are brand-agnostic. In other words, you may plonk them into any 3D Blu-ray player to enjoy your stereoscopic kicks.

3D-ready AV Receivers

It's best to use a 3D-ready AV receiver for a 3D home theater setup. One example is the Onkyo TX-SR608 as shown above. Such AVRs are not only capable of decoding and transporting the new full HD 3D format given their HDMI 1.4a support, but they are also able to process "HD" surround sound standards, such Dolby TrueHD or DTS-HD Master Audio found on 3D Blu-ray titles.

Workaround: If you prefer to retain your non-3D compatible receiver, here's what you can do. Connect your 3D Blu-player to your TV via a HDMI cable. For audio, wire a S/PDIF cable from your TV to the AVR. Also, you might have to tweak the receiver's audio delay option to compensate for any lip-sync offsets. 

HDMI Cables

In early 2010, the HDMI Founders decreed that vendors are not allowed to market HDMI cables based on HDMI versions. In other words, cables are now ranked according to their speed and network capabilities instead. The five classifications are: HDMI Standard, HDMI High Speed, HDMI Standard with Ethernet, HDMI High Speed with Ethernet and HDMI Standard Automotive.



The bottom line is this: as long as you have a High Speed HDMI cable to sustain the increased data throughput, it should be able to transport 3D signals between your AV peripherals without a hitch. Some of the older (HDMI 1.3) cables can work just as well with 3D signals. As such, you might want to test them out before discarding them for good.   

3D Movies via IPTV

Purchasing 3D Blu-ray discs can be a costly affair, and some of us might not relish spending our hard-earned money on something we may only watch once. If you feel the same way, then you might want to consider alternate 3D sources instead. Locally, we have the option of subscribing to Singtel's mio TV Video-on-Demand service which comes with a handful of 3D films such as "Tron" and "Tangled" in HD resolution. As it stands, a single 3D VOD movie would cost you about $6.42 for two days rental.

Some Final Words of Advice

Perhaps a few questions are due before you empty your pockets on a 3D TV. Consider these. For starters, is 3D essential to you? How often would you (and your family members) watch or game in 3D? Are you willing to pay for an AV upgrade? We have to agree that the entire 3D shebang isn't an absolute sham. Experiencing a movie in 3D can be enjoyable for some, especially for the first time. Children may also think it's fun and engaging thanks to the added depth perspective. However, whether these kids (or anyone for that matter) are able to sustain a 3D movie in its entirety is another point of contention altogether.

Let's not forget about practical concerns as well. For instance, active-shutter glasses aren't cheap, and it will cost you a fair bit to cater for a larger group of family members. Also, these shuttering glasses flicker when viewed under fluorescent lighting. This won't do if you prefer to have the lights on. Eye-fatigue is another health risk. Although we've established that polarized 3D lenses cause less strain on the eyes, we cannot speak for the masses emphatically. After all, everyone embraces 3D in a different way.

As revealed in one of DisplaySearch's market research studies, it is not entirely surprising that 3D is one of the weakest drivers behind new TV replacements in various countries, with the exception of Indonesia. In fact, LED-backlit requirements are higher up on consumers' lists compared to 3D. With that note, we hope you've gained a better understanding of 3D TVs after reading this buying guide. We also hope you are now better equipped to tackle the show floor with confidence. If you've decided against a 3D TV, and is opting for a vanilla HDTV instead, well, we've another guide you could turn to.

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