Ever since the invention of high definition, we've been saying how crucial a truly big screen is if you're to appreciate the extra detail.
While that rings truer than ever, there's a flipside; anything watched in standard definition looks decidedly ropey on a screen as big as this. A live broadcast of the FA Cup Final on ITV looks soft in the extreme, despite plasma tech generally being much kinder to standard definition pictures than LCD panels.
Our advice is to avoid TVs over 32-inches in size that don't have Freeview HD tuners – and it's an absolute must at this size.
More concerning are some noticeably jagged edges around Wembley, and motion artefacts around players when we switched to ITV 1 HD, though we suspect that it's got more to do with ITV's compression technology than the 50PK990's shortcomings.
The popularity of HD is soaring, so it's a plus to find a screen so competent with the new MKV digital media format. These HD video files can be scanned-through with ease and enjoy pin-sharp detail, though they can suffer from a little motion sickness.
Meanwhile, Blu-ray enjoys some giddying smooth motion and, therefore, a jot more detail. It's no sharper than a good LCD or LED TV, but the 50PK990 binds some meticulous close-up action with heaps more contrast than the rival flatscreen tech.
Our Blu-ray test disc Sherlock Holmes features many muted scenes, but the 50PK990 manages to pick-out enough details in the dark even with the brightness lowered.
That said, LG isn't at the end-game when it comes to contrast; it's got more work to do if it's to reach the heights of Panasonic's latest plasmas, but there's enough here to help bring out some vivid colours that help lift the action from the screen.
The THX Cinema preset, in particular, proves an excellent showcase for the 50PK990's skill with colour.
That TruBlack filter does make a difference – and leaves it ahead of rival LED sets – though equally important to the 50PK990's success is its ability with motion.
Frenetic sequences do involve a modicum of judder, but it's not a major issue; whereas LCD TVs need to engage a special 'film mode' to make the picture smooth and watchable – the side-effect being some fizzying around moving objects – no such troublesome tech is needed here.
Colour is one of the 50PK990's strong points overall, though again, all's not perfect. Skins tones, especially, can seem a touch too rosy, though there's enough delicate nuance to colour to help Blu-ray discs really sing.
Another leg-up on LCD is plasma's wide viewing angle; watch from off-centre and both colour and black areas of the picture hold their ground.
Benefits of plasma
Overall there's enough here to convince us that, picture-wise, you're more likely to find a truly high-end screen if you stick to plasma (the exceptions being some of Philips' expensive LED screens).
If ultimate picture quality is indeed your goal, we'd recommended checking out Panasonic's latest plasmas.
Conversely, LG has some temptingly lower-priced versions of the 50PK990 if price is more of an issue. Also available is a near-identical 60-inch version in LG's flagship PK990 plasma range, though it's worth seeking the cheaper PK790 and PK590 screens – the former drops TruBlack, and the fatter latter leaves out TruBlack and Net Cast.