Product Type: SMART 3D TV
Reviewed By: Stephen Dawson
Magazine: S&I 24#8
Distributor: LG Electronics Australia Pty Ltd
Who Sells What/Website: LG Electronics
This year Korean electronics giant LG Electronics is being adventurous when it comes to 3D. Instead of using the same technology as the other manufacturers — indeed, the same as it used itself last year — it has taken a radically different approach in its new lines of 3D TV, including this 47LW6500.
The essence of 3D TVs is in delivering, somehow or other, separate vision to each of your two eyes. Since last year the method for home TVs has been sequential — that is, the image for your left eye flashes on the screen, then an instant later it disappears to be replaced by the image for your right eye.
To achieve this eye-by-eye delivery, you wear special glasses with the lenses made of liquid crystal screens. These flash between opaque and transparent in time with the pictures appearing on the screen. If all works well, then each eye will see only the image intended for it.
When 3D TVs first appeared last year, “all working well” was the difficult part. Most TVs had quite a bit of leakage of image from one eye to the other, leading to ghosting. Your left eye would see something intended for the right and vice versa, so objects on the screen would appear to have translucent ghosts beside them.
In addition to being very inaccurate, this tended to reduce the effectiveness of the 3D.
Plasma TVs seemed to be quite a bit better on this front than LCD ones, and there was even some variation between LCD ones.
That was last year. This year, as you’ll see from the models reviewed in this issue, most brands have persisted with shutter glasses, and some seem to have improved their performance a great deal. But with this TV, LG has gone in a different direction.
It doesn’t use shutter glasses at all, but passive glasses. These are like those used at most 3D cinemas. In fact, LG forgot to pack some into the box with this review TV, and I found I was able to use the actual cinema ones to just as good effect. (I was provided the real ones later, so what follows is based on the full LG kit.)
With this TV, rather than the left and right eye images being displayed in sequence, they are both shown at the same time. The separation is achieved by means of polarisation. Light waves have a twist, either clockwise or counter clockwise. Filters can allow through either one or the other.
Half the screen’s pixels are filtered to allow only the light with a clockwise twist to emerge, and the other half allow only the anticlockwise light to be seen. Matching polarised filters in the glasses let each eye see only the half of the image intended for it.
Now if you read the last paragraph closely, you will realise that with 3D content, each eye only sees half the pixels. But which ones?
LG has put the different polarisation on alternate horizontal rows of pixels. This polarisation is a physical filter applied to the screen, using a film technology developed by LG.Chem, the company’s chemical division. So when you’re watching 3D content through the polarised glasses, each eye sees only every second row of pixels. So the 3D resolution of this TV is therefore 1920 by 540 pixels, rather than full-HD 1920 by 1080 pixels.
We will return shortly to see how this looked in practise.
The TV is a 119cm model with LED backlighting. Despite being only 30mm thick, the LEDs apparently aren’t edge LEDs, but a proper rear 16-block array. This gives a modicum of independent brightness control in different sectors of the screen.
The TV also has a frame interpolation motion smoothing system built in (called ‘TruMotion’), and is loaded with what is called these days
‘Smart TV’ functionality, with network support and access to online content.
Since the eyewear has no active components, they are extremely light. The glasses supplied with the TV weighed only 16 grams (compared to 23 grams for cinema-issue ones).
We were fairly impressed with the 2D performance of this TV. The 16 blocks of backlighting were, perhaps, a bit too coarse to give the real velvety blacks in high contrast scenes, but they still gave better results than most LCD TVs. There were very few instances of mottled black through backlight breakthrough. Picture brightness was excellent.
I found that the default sharpness was a bit too high, but you have to be cautious with the sharpness control on this TV (see also our article on p80-81). Unlike most TVs, turning it down to zero actually softens the picture well beyond the sharpness of the incoming signal. I’d also suggest you turn off the TruMotion motion smoothing system; it gave a quite inaccurate gloss to the overall picture.
Amongst the Smart TV material available was a bunch of apps which could be downloaded, Bigpond TV and the Bigpond subscription movie service, Channel 7 and ABC catch-up TV access, and Facebook. YouTube didn’t appear on the front page, but you can hit the ‘+’ icon and load in this capability.
The TV also supports the HDMI Audio Return Channel. But it demands that you work a bit to achieve this function. There are two very separate places where you have to enable it... neither is alone sufficient; both are required. Still, having easy access to high quality sound from a home theatre system was very useful.
But here I want to focus on the 3D performance in particular.
The polarisation system has a number of advantages. One is that there are no flashing shutters in the glasses. That makes them cheap and light. You can buy more from LG for $19 for two pairs. But they give you four pairs with the TV, so you are unlikely to need more, and in any case you can use those cinema 3D glasses that you may already have purchased.
Also, some of the flashing glasses can create a perceptible flicker, either with the picture or through interference with room lights. None of that with these.
And the ghosting or crosstalk on 3D content is extremely low. You have to look hard to see any of the image intended for one eye appearing in the other. Consequently, the 3D effect tends to pop out rather impressively. I used the Werner Bloos test again, and while not delivering quite 100% crosstalk rejection, it came close. It also avoided the colour shift of greys which generally appears with other systems.
But there is a cost for this, at least as of 2011. The lower resolution of the TV is visible. High contrast diagonal lines, in particular, show marked jaggies — a kind of step-like pattern where there should be smoothness.
There is also some loss of detail. This is particularly true of side-by-side 3D material, as used on broadcasts, because side-by-side 3D halves the horizontal resolution from 1920 to 960 pixels, since it shows both images at once. Coupled with the LG’s vertical halving, that left the effective resolution at 960 by 540 pixels for side-by-side 3D.
But even then, the 3D effect simply popped; it was utterly effective. So surely this is the way of the future for 3D TVs. The trade-off is worth it even now for the more perfect 3D performance and the far friendlier glasses. And in a few years when the resolution of TVs has doubled, it will be even better.
The 2D-to-3D conversion facility seemed to be generally more aggressive in its action than other such facilities that I’ve used. That can be good, or bad, depending what you want from it. Some processes are so cautious — presumably in an effort to avoid unrealistic results — that you barely ever see a 3D effect at all. This one was anything but cautious. The results were inconsistent. Much of the time they were spot on and very impressive, with the fore-aft array aligning nicely with what you’d expect. But occasionally things would become confused. For example, in one early scene in The Searchers, a girl wearing white appears for a moment to be closer to the front than the character next to her, even though she is actually further back. Presumably the TV was tricked into bringing her forward because she was brighter and more central than the other character. There were also quite a few scene changes where the 3D perspective would change an instant after the scene change, as though the processor needed a frame or two to work out what to do.
With all presently existing 3D TVs you have to choose your defect of choice. For many the reduced resolution of this one (remember, the resolution is only halved when watching 3D) will be more than amply compensated by the flicker-free performance, the user-friendly glasses and the excellent 3D sense of depth realised by the near complete elimination of crosstalk. Stephen Dawson
These close-ups show the effect of the polarised eyewear worn for 3D viewing on the LG (don’t wear them when watching 2D, because you will unnecessarily lose half the vertical resolution).
The first shot is a close-up of a diagonal line of the screen in full resolution. Each tiny square is a screen pixel. The second shot is taken through one of the lenses of a set of 3D glasses. Notice how every second row of pixels is blanked out by the polarising filter on the screen. Detail inevitably suffers, but the 3D effect is excellent, and the glasses are far cheaper, battery-free, and more convenient to wear.
In less than a year, LG has shed another third of its power consumption, bringing it down from the 47LX9500’s 101W to this one’s 67W. LG rates this TV with a seven-star energy rating and an annual consumption of 280kWh per year. Our figures suggest eight stars and 248kWh. Either way, this is a very economical unit in terms of power use.
LG 47LW6500 LED-LCD TV
Excellent 3D performance
Very good 2D performance
3D eyewear cheap and light
Half vertical resolution on 3D
No auto lip sync
Display technology: LCD panel, LED backlight, 16 blocks
Screen size: 119.4cm
Native aspect ratio: 16:9
Native resolution: 1920 x 1080
Brightness: Not stated
Contrast ratio: 9,000,000:1 dynamic
Inputs: 2 x composite video, 0 x S-Video, 2 x component video, 1 x D-SUB15 RGB, 4 x HDMI, 4 x stereo audio, 2 x USB, 1 x Ethernet, 1 x aerial
Outputs: 1 x optical digital audio, 1 x 3.5mm headphone
Audio: 2 x 10W
Included accessories: Table-top stand, remote control, 4 x 3D glasses
Dimensions without stand (whd): 1119 x 684 x 30mm
Weight without stand: 18.2kg
Warranty: Three year