LG Cinema 3D Passive TV Review

As LG launch the LG Cinema 3D passive TVs in the UK this week, 3D Focus gives our first impressions of the new 3D TVs and asks, ‘Is passive 3D technology in the home what the 3D TV market needs to drive up popularity’?

At CES 2011, LG announced there were bringing passive 3D TV technology to the living room with their new Cinema 3D TV range. By utilising film-type patterned retarder technology, LG claim to be offering all the benefits of passive 3D TVs such as flicker free images, cheap light weight glasses and brighter pictures for about a quarter of the price of existing passive 3D TVs.

Now the public can decide as UK retailers take their first stock and LG begin a UK nationwide tour to demo the cinema style technology. One thing is for sure, after being shown some stunning Korean 3D productions on the new LG cinema 3D range during MIPTV, 3D Focus is convinced passive 3D TV is going to transform the 3D TV industry.

Disclaimer: 3Dfocus.co.uk has no commercial affiliation with LG Display.

Please note – This is page 1 of 3.

Let’s back up for a second. Even though most people reading this 3D news website will already know what I am about to write, for those still confused by the two main types of 3DTV technology available, here is a brief summary. Click here to go straight to the LG Cinema 3D range review.

Active 3D Technology

The most popular type of 3D TV sold in the UK and around the world incorporates active technology. The reason for this is due to economics. In the active system, the technology that creates the 3D effect is incorporated into the 3D glasses, rather than the 3D television set. The active glasses (also known as shutter glasses) require their own source of power (a rechargeable battery) to rapidly open and close each lens.

With all type of 3D, each eye needs to see a slightly different image. Therefore, when the left lens is ‘closed’ (the liquid crystal display turns to black preventing light from the 3D TV to reach the left eye), the right lens is opened (it becomes opaque) and the TV displays the image intended for the right eye. Next, the right lens will close and the left lens will be open. The TV then switches its output to the image intended for the right eye.

This process happens sequentially and so fast (up to 480 times a second although only 50 unique frames of a 3D image are delivered per second in a PAL TV) that the brain merges the two images together in a process called binocular fusion. This creates the illusion of images going in and out of the screen, the extremity depending on the extremity of distance between the two images (or interoccular difference). The syncing data (which is required so the television can switch images and lenses in sync with each other) is usually sent via an infra-red signal to the glasses although all new Samsung 3D TVs will be using Bluetooth radio frequencies.

The reason it is so economical to release active based 3D TVs is because it is relatively cheap/easy for a 3DTV to switch images very rapidly. The technology is a processing one rather than a physical change to the TV set and it is the 3D glasses which feature the majority of the expensive technology to enable the 3D effect. Hence 3DTV manufacturers can charge up to £100 for each pair of glasses but keep the cost the 3D TV set very low. Also, most mid-range 3DTVs will only include a couple of pairs of 3D glasses – not very conducive for communal viewing which is ironic when the UK’s only 3D channel, Sky 3D,  places so much emphasis on 3D movies and sports (often enjoyed in groups).

Passive 3D Technology

The other main type of 3DTV technology is known as passive (and is what the new LG Cinema 3D range uses). It is the same type of technology deployed in most 3D cinemas. If you have watched a 3D movie, the chances are you would have put on a pair of Real D glasses. This is passive technology and is why LG have branded their new passive range as ‘Cinema 3D’ to leverage the popularity and wide knowledge of 3D in cinemas.

In this case, the opposite is true. The expensive technology is in the actual 3D television set rather than the glasses which allows for very cheap (almost disposable) 3D glasses.

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How Do Passive 3D TVs Work?

As with all 3D technology, a passive 3DTV needs to send a different image to each different eye. Unlike shutter glasses technology, a passive 3DTV will send both images at the same time. However, the vertical resolution of each frame is split into alternating lines. So, the first line will display the first line of the left image, the second line will show the first line of the second image, the third line will show the second line of the left image etc.

Overlaying the display is a physical screen or ‘film’ called a film patterned retarder or FPR. This consists of strips which perfectly align with the vertical lines of the display. Each of these strips polarises the wavelength of the light being outputted from the screen. This means the waves of light are converted into a uniformed direction. The only way to view the polarised waveform is by viewing it through a matching polarised filter. Passive 3D glasses have two lenses each with a different polarising filter.

Passive 3D TVs have been around for a while – what is so new about the LG Cinema 3D range?

You might be asking why this new? There have been passive 3D television sets on the market for a while now. Well, it is all down to the fact that LG Cinema 3D TVs are being sold at dramatically lower cost point than existing passive 3D TVs and that they are LED rather than plasma/LCD displays. It is said that the film patterned retarder technology has reduced the cost of passive 3D sets to around a quarter of existing passive 3D TVs. Before FPR, polarising glass substrates had been added to the display to achieve the polarisation of the images which has added a considerable premium to the cost of the 3D TV set. LG have installed a cheaper ‘film’ so passive 3D technology can be ready for the consumer market (the passive 3D TVs in existence right now tend to be used in corporate or showcase environments).

Passive V Active Technology

Due to the way they work, active 3D sets give out a horrible flicker effect as the glasses rapidly close and open each eye. Active 3D TV manufacturers claim that the process happens so fast that the brain can’t notice the flicker. However, everybody who I have spoken to who have watched an active 3D TV in a store demo or who have reviewed 3D sets often complain about this artefact.

I probably should not admit this but I do not own a 3D TV even though I run a 3D news website. For me, current active 3D TVs on the market are not up to the job in offering a comfortable immersive 3D experience mainly due to the inherent flicker artefact. The flicker is even worse in florescent lighting and the glasses are heavy, bulky, expensive, uncomfortable and often loose sync. During the MIPTV market, so many of the active 3D glasses I looked through malfunctioned – it was hardly a glowing endorsement of 3D TV. Because the glasses are expensive it is unlikely that one can watch 3D programmes with other people too. Plus, there are compatibly issues between manufactures although that issue is being addressed with standardised glasses on their way.

Advocates of shutter glasses technology point out that the viewer is enjoying full HD images per eye and that the technology has enabled 3DTV to be delivered at an affordable price point. To a certain extent that might be true. You can now buy an active 3D ready TV for about £500; it has enabled 3D TV technology to enter the home. Also, passive glasses do halve the vertical resolution of the image so the viewer is never enjoying true HD which the shutter glasses system does offer. More on this later.

LG have attempted to address these problems with its new Cinema 3D FPR range and I got the opportunity to view them during the recent MIPTV event.

CLICK HERE FOR PAGE 2 – LG CINEMA 3D TV RANGE FIRST IMPRESSIONS

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