Latest Site Articles Learn how 3D TV works Easy to follow guide to the 3D TV technology used to deliver 3D imaging. Answering the question 'how does 3D TV work?'
Is watching 3D bad for your health?
Examining the latest published 3D TV health warnings - is watching 3D images bad for your health?
Discover the parts that make up the 3D experience.
Revealing what you need to watch 3D TV - an introduction to the TV sets, Blu Ray players, and glasses.
The why, what, how, where, and when of buying a 3D TV.
The top 'need to know' facts you'll want to consider when looking to buy a 3D TV.
Where can I get more info on 3D TVs, Blu Rays, glasses etc
One of the best ways to get good information on any subject is by participating in forum discussions. Here you'll find a good choice of 3D TV forum threads chosen for their interesting discussion value.
3D TV Manufacturers - The latest developments and models from the leading TV manufacturers - Toshiba Samsung Mitsubishi
Panasonic Sony LG Vizio
Phillips Sharp
3D TV Models - Revealing the latest new 3D models to hit the stores.
3D TV Networks - Get the lowdown on the 3D content providers, and find out who has plans for dedicated 3D channels - Cablevision, Cox, Time Warner, Comcast, DirecTV, Verizon, Sky
Why 3D Glasses Are Needed For Viewing 3D Images On TV
LCD Active Shutter or Passive - Understanding The Difference
The need to wear 3D glasses to play 3D games and watch content such as 3D movies on 3D TVs or using 3D Blu Ray is one of the most widely discussed topics both within the 3D TV manufacturer industry, and among us the 3D TV buyers.
Until the arrival of good quality, low cost 3D TV without glasses this requirement to wear 3D glasses is likely to continue shaping the widespread acceptance of 3D TV as a home entertainment medium.
Fortunately, the major manufacturers are aware of the limitations and issues that 3D glasses impose. They are a problem not only from a cost perspective (although the newer Passive glasses are much cheaper than the widely used Active Shutter models) but many pairs often often only work with the manufacturers TV that they've been designed for, meaning you can't wear them to watch different TVs. On top of this, most 3D TVs only come bundled with one or at the most two pairs. You'll need to buy extra pairs for family or friends. Buying a 3D starter kit - where you get extra pairs provided - is one way of overcoming this problem.
Ever since Avatar, Clash of the Titans, and Alice in Wonderland illustrated our appetite for 3D fare, electronics companies have been clamoring to bring the experience to our homes. But 3D isn't a new invention. In fact, it's been around for almost a century. The first 3D glasses and movie appeared in 1922, and the technology carried on through to the the 80s until the viewing public lost interest.
In recent years developments in 3D TV technology have moved on. For anyone wanting to know how 3D TV works, understanding the part 3D glasses play is critical, especially for anyone looking to buy a 3D TV at this stage. With the increasing availability of content from 3D TV networks and the 3D TV channels that they carry, the stage looks set for a growth spurt in the take up of 3D television into our homes. The debate over whether 3D glasses will have a negative impact on these growth prospects will continue to rage on for some time.
In this article we'll look at the reasons why we need to wear 3D glasses, what types of 3D glasses are available, the different types of 3D glasses - active LCD shutter glasses and passive glasses - and the technology behind them.
So, why do we need to wear special glasses for viewing 3D content? The answer lies in the way that our brains interpret images received by our eyes. For this, we need to understand parallax and how it works.
The best stereo images come from delivering different images to each of our eyes, and the easiest way to accomplish that when viewing a flat image is to wear glasses with lenses that deliver slightly different versions of that flat image to each eye.
Humans naturally see in 3 dimensions due to parallax, which is the overlapping line of vision that occurs when using 2 eyes to view an object. Since our eyes are several centimeters apart, each eye sees an object at a slightly different angle. This slight difference is what causes ‘depth perception’ and our experience of seeing in three dimensions. This is known as stereoscopic imaging. When movies came along, there was more experimentation with parallax and the search for more effective ways to manipulate viewers’ perspectives. Originally, 3D images were produced using anaglyph images, created by superimposing a red tinted image over a blue one at a slightly different perspective. Cardboard 3D glasses with red and blue lenses were necessary to see the action jump off the screen.
Our eyes see combinations of the three primary colors: red, blue and yellow. Anaglyph 3d glasses simply use a different colored lens for each eye. The anaglyph glasses paired one primary colored lens (like red) with one mixed colored lens like cyan (a mixture of green and blue). This created 3D images by blocking out parts of the color spectrum in one eye, and different parts of the color spectrum in the other eye. The difference between the two was enough for each eye to see a slightly different image while looking at the movie screen, causing the brain to process the scene as if it were three dimensional.
The process allowed for 3D viewing, but caused incredible color distortion. A change was made to polarized anaglyphs - images with different light levels rather than colors - but by then it was already too late. The public had moved on. Recently, however, the desire for 3D content has been reawakened forcing new developments in polarized glasses. Avatar has shown that 3D doesn't have to be a gimmick. It can be an art form. The glasses used in cinemas are know as passive glasses, cheaply made and highly effective in a cinema environment.
Passive 3D Glasses At Home - Understanding The Difference Between LCD Active Shutter & Passive Glasses
The key difference betwen the two types of glasses is that while passive glasses create 3D imaging by sending information to each eye of our eyes in sequence, active glasses do so by sending information to both eyes simultaneously. Passive glasses are similar to those you get when watching a 3D movie at the cinema. They're polarized glasses which separate the images you see, and only let the correct image intended for the left and right eye be seen by the correct eye.
One of the main benefits of passive glasses is cost, with a pair potentially costing around a pound or a couple of dollars. In addition to this there's no power, so no batteries to replace.
The trouble with polarized anaglyph glasses is that they require darkness to work to their fullest. It's hard to create and maintain the darkness of a theater inside a living room, so companies had to find a way to produce 3D without tampering with an image's light levels.
The most recent development in passive glasses has been the arrival of FPR or Film Patterned Retarder technology. This is now being championed by the likes of LG, Toshiba, and Philips, and works by optimizing the separation of images for our left and right eyes, and then converging them again through the passive 3D glasses to deliver the 3D image.
This creates superior 3D images with reduced cross-talk or ghosting, a problem which can result in blurred images. New LG 3D TV sets use a thin film covering the screens that helps to counter against the light level problem previously seen with passive glasses, and results in brighter 3D images for a good quality 3D viewing experience.
Vizio were the first of the manufacturers to introduce this passive 3D technology in late 2010, with the release of their 65 inch XVT3D650SV model - an expensive purchase at the time at around $3700. Initial tests showed some difference in picture quality when compared to one of the popular Panasonic active glasses sets, with the best picture delivered by the Panasonic.
3D LCD Active Shutter Glasses
Originally developed for gaming and viewing display screens, 3d shutter glasses have now evolved into being used to watch high definition 3D TV. This active shutter glasses format gives clear, high quality, high resolution images. Shutter glasses work on the same basic principle as red and blue disposable glasses or polarized passive glasses; letting one image into each eye.
Instead of playing with colors or light levels, though, shutter glasses actually darken or close each lens in time with a television's refresh rate at a speed of around 120 times per second in a technique known as alternate frame sequencing. This allows one image to enter the left eye while the right lens darkens, and vice verse. It happens at such a fast speed, controlled by an emitter built into the TV, that you don't notice the darkening but do see three dimensions. It's this process that makes them significantly more expensive than passive 3D glasses, and because they're electronically controlled they also need rechargeable batteries to operate.
. Samsung has a slew of shutter glasses coming out alongside their 3D TVs and 3D BluRay players in 2010. All require batteries to power the lens shutters, but the SSG-2200AR is the only rechargeable model. The SSF-2100AB model, which uses disposable batteries, also will be available soon. Both of these models will be available only in single pairs of glasses, running between $150 and $200 each. For consumers needing more than one pair of 3D glasses, Samsung will also offer a 3D starter kit, which includes two pairs of their SSG-P2100 glasses. For those consumers who can't afford $150 for a single pair of glasses, ViewSonic offers a less expensive option: its PGD-150 glasses for only $89. These 3D glasses can be used with other 3D-capable devices and have an effective viewing range of up to 50 feet. I-O Display is jumping into 3D, as well. The company is releasing its Virtual FX 2D-to-3D converter, complete with two sets of shutter glasses. There have been a few 3D TV health warnings issued, mainly around the health concerns with shutter glasses, however. Extended viewing through shutter glasses can cause disorientation and headaches. Wearing the glasses for extremely long periods - such as days at a time -- could even cause potential eyesight damage.
Shutter glasses may seem like a slightly complicated piece of technology, but they work very easily. Some companies may say the glasses need to be “sync'ed” to the TV, and offer to do it for you for a nominal fee. But you can sync your glasses to your TV at home, free of charge. All it takes is wearing them and looking at the screen.
Incompatability Issues - and the potential solution....
Incompatability between 3D glasses for different manufacturers sets has always been a stumbling block for 3D TV. So the recent moves by Panasonic to create a single standard for active shutter models look to be a promising step in the right direction. They've worked with Xpand3D to create a standard known as M-3DI, which is intended to give compatability for glasses used with all the different types of 3D displays - TVs, PCs, laptops, and projectors.
The standard has the backing of a number of major manufacturers including Mitsubishi, Hitachi, Panasonic of course, and a handful of others. It's expected that the new technology will be seen first in Australia in the latter half of 2011 when Panasonic release their new high end plasma 3D TV range, and works by using two-way technology whereby once a set of 3D glasses are activated they will recognise which TV brand and model the user is watching.
Copyright 3DTvGuide.org 2011
The War Between Active & Passive Glasses Technology - Latest Developments & Additional Resources
The major manufacturers are split on which types of 3D glasses to focus their ongoing developments. Samsung, Sony, Panasonic, and Sharp are continuing their 3D developments with shutter 3D glasses - LG, Philips, and Vizio are focussing on passive glasses. Toshiba stand alone with intentions to focus on all 3D TV display technologies - active, passive, and no glasses at all.
LG recently announced intentions to focus on FPR Film Patterned Retarder technology. This makes use of polarized passive glasses in a way which could reduce the health worries. They believe that FPR 3D TVs give full HD 3D quality images without any image overlaps or flickering. The counter argument from Samsung is that resolution levels using passive glasses are not at the right level for full HD.
Because of the way passive technology works by showing two 1080i frames at the same time, this results in losing half the resolution of the image compared to an active glasses set. There are fewer pixels involved in creation of images, thus in theory they might be slighly blurred.
Initial reviews of LG's and Vizio's new passive glasses sets suggest that the problems most often encountered with active 3D TVs - namely crosstalk and flicker - are not apparent and that overall picture quality is good. This does raise the possibility that passive glasses technology might be the answer to the glasses problems. The recently released Vizio VT3D650SV in particular has been getting excellent reviews.
Of course, it's possible that there will be no outright winner until either 3D TV without glasses models take centre stage, or developments in universal 3D glasses see some expansion. Availability timescales for no glasses 3D TVs are unsure, but on the universal glasses front there are already some promising developments under way, with Panasonic teaming up with XpanD to deliver standard compatability across all 3D capable devices.
The Japanese company Sanwa has recently announced that its new 400-3DGS001 3D glasses are compatible with multiple manufaturers of 3D television sets. They're not truly universal in the sense of the word - reportedly compatible with Sony, Sharp, Toshiba, and Panasonic sets - but the progress is definitely encouraging. The Sanwa 3D glasses work by recognising the TVs infrared signals, and come equipped with a select button which lets you choose the type of 3D TV you're using.
Another company called Volfoni demonstrated their universal glasses at CES 2011with a line called Activeyes, which give you the option of switching between active and passive modes. Reports suggest these are compatible with all makes of 3D TV currently on the market.
Feb 2011 - Samsung have teamed up with Silhouette to unleash a new set of ultra lightweight 3D glasses known as the SSG-3700CR. The model weighs an impressive 27g. With the requirement to wear 3D glasses causing issues for many consumers, LG and Samsung have both been looking at ways to redesign. The revolutionary design ensures a fit for both adults and children, with a clever balance of weight distributed between front and back.
Nov 2010 - Leading Italian fashion house Gucci have announced plans to sell their own model of 3D glasses. Cost is reportedly expected to be in the region of $200 a pair.
Useful Links
www.3DGlassesReport.com - Quickly growing into one of the most valuable online resources covering all types of glasses for 3D viewing.
www.3dglasses.net - As the site name implies. One of the leading websites dedicated to bringing in depth info on different types of glasses for 3D viewing.
www.optionsonline.net - Looking for guidance around the health issues that might be encountered among 3D glasses wearers, and the impact on regulr spectacle workers.
ePanorma.net - In depth article covering the technology behind 3D glasses.
