3D TV is going to take the home entertainment world by storm and is the next big thing since…..the last big thing (whatever that was).
Well, that’s what the consumer electronics manufacturers are hoping for anyway!
If there’s one thing that the HDTV and movie companies are getting very excited about at the moment, it has got to be 3D TV.
Now the cynics among you will shout that this is just because they’ve found another way to make us replace all our AV hardware again… and you’re probably right.
However, let’s not get sidetracked by the reasons for it. Instead, let us take a look at 3D technology and see what it means for us.
How does 3D technology work, and what hardware will we need in order to make the most of it?
Once we understand this, then we are better placed to make a decision on replacing our existing equipment… or not.
A Brief History of 3D
The idea of using 3D images for movies and television has been around for quite some time.
In fact, the technology dates from the late 19th century and the first 3D movie was actually shown in 1922.
There have been various periods over the years where 3D movies and television became popular for short periods, such as during the 1950s in America, but it has never taken off and remained mainstream.
In the 1980s, there was another craze for watching movies in 3D, and a number of releases, such as Jaws 3-D, used this technology.
The way it worked in those days was that we had to wear a cheap pair of cardboard ‘glasses’ while we watched the movie. These had a red lens over one eye and a cyan lens on the other side.
Coupled with a special stereoscopic filming technique, the glasses enabled the image on the movie screen to appear to have a 3D effect.
We were able to see a depth to the image as some objects appeared nearer than others.
For the technical types among you, this particular technique is known as anaglyphic 3D.
There were always a few special effects throughout the movie where something would leap out from the screen and make us jump. Oh yes, we really knew how to enjoy ourselves in the old days!
However, the demand for 3D gradually faded, and although it never disappeared completely, 3D images have usually been seen as an interesting gimmick rather than a proper alternative to 2D images.
And why did it fade away? Well, because it was a bit rubbish, really. It never really looked that good and often just gave you a headache.
So 25 years after the last 3D craze, here we go again. 3D is all the rage, and it’s time to get your 3D specs out once more.
Even though the technology has developed over the years (aided by the introduction of digital technology), the most common forms are still based on the principle of wearing a special pair of glasses in order to see the 3D effect.
So how does 3D work, and what is different about new digital 3D technology?
How Does 3D TV Work?
Although there are other methods, stereoscopy is the most commonly used method of creating 3D images for television and movies.
Stereoscopic images use two slightly different perspectives of the same image, which means our left and right eyes see slightly different views of the same thing. Our brain then creates one image from these two different views, and it is this that causes us to see 2D images with the depth of 3D.
There are four main methods of producing stereoscopic 3D images for television and movies:
- Anaglyphic 3D: uses passive glasses with two different color lenses – usually red and cyan
- Polarization 3D: uses passive glasses with polarized lenses to create different images in each eye
- Alternate-Frame Sequencing 3D: uses active shutter LCD glasses which synchronize with the display and very quickly open and close each lens to view different frames of the movie
- Autostereoscopic 3D: doesn’t need glasses to see the 3D effect – a mask or lens is placed over the screen to send different images to each eye
Of these four methods, it is polarization and alternate-frame sequencing (aka frame-sequential 3D) which are mainly being used.
3D in Cinema
A passive 3D system using polarized glasses is the type most often used in cinema – the most common system being RealD Cinema. This method provides an effective 3D effect and polarized glasses are relatively cheap to make.
So, it is the most cost-effective way of providing 3D to large audiences.
However, there are alternative 3D systems currently being used in cinemas around the world such as Dolby 3D, XpanD 3D, MasterImage 3D and IMAX 3D. All of which use slightly different methods to create a similar 3D effect.
3D in The Home
For 3D images in our homes, many manufacturers are going to be using frame-sequential 3D in their HDTVs. Many of the new 3D flat-screen TVs will use this active 3D technology and this will require us to buy the more expensive active shutter LCD glasses.
The main advantage of active 3D systems is that they will deliver Full HD 1080p images to each eye, whereas other methods will have to rely on lower resolutions.
However, some TV models will use passive 3D with the cheaper polarized glasses, and so this is one area that we will need to be aware of when we are buying a new TV.
The two technologies will have certain advantages and disadvantages, but the main point is that we will have to buy the right type of glasses to suit the technology our TV uses.
Existing 3D Technology
Some people might be confused by all this talk of ‘new’ 3D TVs when they have been watching 3D on their old televisions for years. The difference is that they would have been using the older anaglyphic 3D, or possibly field-sequential DVDs which worked on old CRT televisions.
Anaglyphic 3D can be seen on any TV as it is created by displaying a picture with two color-filtered images superimposed on each other. When viewed with good old red and cyan lens glasses, a 3D image is seen.
However, anaglyphic 3D isn’t as accurate as digital frame sequential/polarized 3D, which provides sharper 3D images with more accurate colors.
So all the recent talk about 3D TV in the home is referring to ‘new and improved’ frame sequential or polarization 3D.
I agree with you, it is confusing.
3D Hardware – TVs and Blu-Ray Players
Ok, so now we understand what 3D is, what exactly will be needed in order to have this in our homes?
Well, you will need 3 things for 3D (easy to remember!):
- 3D-enabled sources – such as a Blu-ray player or TV transmission
- 3D-enabled display – such as an HDTV or projector
- Sexy 3D glasses – sexy is optional!
So yes, you’ve got that right; you’re probably going to have to replace most of your current hardware in order to experience the joys of 3D in your home.
At present, the easiest way to start watching new 3D content will be to buy a 3D-enabled Blu-ray player. These will allow you to watch standard 2D Blu-ray movies (and DVDs and CDs) but also play any movie that has been released in the new 3D format.
All the major manufacturers of Blu-ray players have 3D models which support this new format. Just make sure that when you are buying a player, you are buying the 3D model.
It can be easy to buy the wrong one by mistake as the players can look very much alike when you see a long list of them. The Sony BDP-S6700 4K Upscaling Blu-ray Player pictured below will play 3D discs.
One technical issue to be aware of before buying 3D devices is that 3D signals are only supported by HDMI 1.4 and above. This means that your new 3D Blu-ray player will have a minimum of HDMI 1.4 connections.
Similarly, your new 3D TV will also have at least HDMI 1.4 connections – meaning you can directly connect the Blu-ray player and TV and get 3D pictures.
However, if you are currently using an AV receiver in your system, then it may well not support HDMI 1.4, so you won’t be able to use it to pass-through 3D signals to your TV.
The only way around this is to connect the Blu-ray player directly to the TV. Which if you only have one HDMI output on the player, means you cannot send HDMI audio to the AV receiver.
Or, you can buy a new HDMI 1.4 AV receiver too!
Broadcast, cable and satellite TV companies were slow to roll out 3D transmissions for their networks.
One of the main reasons was the increased costs required to broadcast 3D than that of standard or high-definition transmissions – and this had to be weighed up against public demand.
The major UK and US satellite and cable broadcasters started to transmit some of their shows in 3D around 2010/2011.
They tried to entice users to use ‘exciting’ free and paid 3D TV channels. However, after 2 or 3 years, these transmissions were gradually discontinued.
The new active (frame sequential) and passive (polarization) 3D technologies will require a television that is 3D-enabled.
To support the high frame rates of 1080p in 3D, an active 3D TV will need a minimum ‘real’ refresh rate of 120Hz (60 Hz per eye).
It will also need an HDMI 1.4 connection (or above) to receive the signal from a compatible Blu-ray player (as mentioned above).
Depending on the type of 3D technology used, these new TVs will also have built-in IR technology to synchronize with the active LCD glasses. This is true of televisions that use frame-sequential 3D.
If the TV is using passive polarization for 3D rather than frame sequential, then the screen needs a polarizing filter over the screen for the passive glasses to work.
So either way, you will need to buy a new television! Sorry about that. If you do, take a look at my reviews of the best OLED and LED TVs available today.
As with Blu-ray players, all the TV manufacturers now supply 3D televisions as part of their range.
You can get 3D models in either LED or the newer OLED technology. So, 3D doesn’t have to limit the type of TV that you buy.
Just make sure that when you decide on the model that you want, you are buying the 3D version.
This is because all the manufacturers also make 2D-only models for those that don’t want 3D TV. Expect to pay a little more for the 3D version.
The type of glasses you buy will depend on the technology your TV uses.
Active systems will require powered LCD shutter glasses, which synchronize with your display. The power will come from batteries which will either need replacing from time to time, or they may be rechargeable.
Due to the complexity of the technology, these glasses will be much more expensive to buy than passive versions.
Passive systems require polarized glasses, and these will be much cheaper than the active versions. Therefore, it will be much easier to have a few spare pairs lying around when visitors come over.
However, a passive system on a flat-screen TV will not support the highest resolutions, and so the image quality may suffer in comparison.
Buying Guide – What to Look For
The main things to think about are:
- What type of 3D TV do you want – passive or active?
- What source of 3D shows do you have?
- Will your new equipment connect with your current home theater system? Especially regarding HDMI 1.4
Like it or not, 3D TV and movies are coming your way.
It will be interesting to see if this technology really captures the imagination of the consumer because if it doesn’t, then the availability and sale of 3D-enabled hardware will be pretty slow.
People are going to need some convincing if they are going to replace most of their home cinema equipment just to get the added benefit of 3D.
Having said that, if the response to 3D images is good, then it may be that 3D technology is finally here to stay.
The ideal technology for the home is autostereoscopic 3D, which doesn’t require the wearing of glasses.
However, this isn’t going to happen any time soon, and so at the moment, we’re going to have to get used to putting on our glasses if we are to enjoy the 3D experience.
About The Author
Paul started the Home Cinema Guide to help less-experienced users get the most out of today's audio-visual technology. He has been a sound, lighting and audio-visual engineer for around 20 years. At home, he has spent more time than is probably healthy installing, configuring, testing, de-rigging, fixing, tweaking, re-installing again (and sometimes using) various pieces of hi-fi and home cinema equipment. You can find out more here.