Before we get onto the 47LW550T's 3D performance, it's worth noting that its hi-def 2D images are excellent.
LG claims a 5,000,000:1 contrast ratio for the 47LW550T, but our lab measured a real-world figure of 262,000:1. That's quite a big difference, but 262,000:1 is still impressive, putting it easily in the upper echelons of current LED TVs. And that objective figure translates to subjective viewing, too.
With Ridley Scott's Robin Hood on Blu-ray, the 47LW550T offers a well-contrasted picture that's capable of displaying peak whites and Emo-grade blacks simultaneously. The opening night-time scene, with torch-wielding villagers surrounded by the forest darkness, is therefore suitably atmospheric and immersive.
This excellent contrast ratio and black level comes courtesy of a stable edge-LED backlighting system (with local dimming) that manages to avoid any trace of light pooling. A 16-step greyscale pattern showed clear delineation without any crushed blacks. Even doubling up to 32 steps only resulted in the brightest whites failing to separate.
Colour performance is similarly commendable. With our own Picture Wizard-enabled preset, tones were bright, believable and full of subtlety. Reds managed to look red, rather than orangey. Again, a reference gradation test showed none of the blocking that afflicts less well-engineered screens.
The 47LW550T falls down slightly with motion. There is a noticeable loss of picture detail with fast horizontal pans; engaging the TruMotion frame interpolation tech, even on its low setting, resolved the problem immediately, but introduces predictable haloing around fast-moving objects. When Avatar's Sully takes control of his Na'vi for the first time and runs around like a loon, we were quick to dispense with TruMotion.
Switch up to three dimensions and the 47LW550T continues to raise a smile, but it isn't without its flaws.
Firstly, despite using passive technology, the 47LW550T still exhibits crosstalk. As always, it's dependant on the material, but anyone hoping this niggling 3D side-effect would be AWOL will be disappointed.
On the plus side, 3D glasses without active shutters means flickering pictures are a thing of the past. Watching Avatar 3D on the 47LW550T was a pleasure, and the fact that having ambient lights on didn't irritate the 3D delivery system was a welcome bonus.
The viewing angle is also good. Move around the room and the picture follows. The same cannot be said of Active 3D systems, where the eyewear can lose sync. However, go off-axis vertically and you begin to notice the horizontal ripples of the screen's filter, especially with bright material.
And what of the resolution loss? Well, it's certainly true that full HD 3D Blu-rays don't look as sharp as their 2D counterparts and if you get close to the screen you can clearly see where horizontal resolution has been chopped in half, but at a normal viewing distance it's much harder to spot.
And even with the resolution loss, the sharpness of the overall picture is impressive; losing half the vertical resolution doesn't mean it's suddenly back to DVD standards. It's more like Blu-ray lite. Whether or not that's good enough for you is a personal choice, but we'd suggest that the positives of the passive 3D system outweigh the negatives.