3D display technology has slowly, but steadily moved from passive to active, but LG has decided to go against the flow and revert to passive technology. However, in order to be completely clear - the switch to CINEMA 3D passive display is anything but a step back, on the contrary. LG currently has four CINEMA 3D TVs in their product gamma, with several display diagonals each. Their characteristics are largely the same, the only difference being the design, vertical refresh frequency, as well as additional capabilities (such as DVB-S tuner implementation). We’ve tested LG’s 47LW5500 with a 47” diagonal, representing the golden middle in the fresh offer of the company.
All models from the aforementioned CINEMA 3D series are based on LED backlight, set around the edges of the panel. This TV’s main feature (the entire series, in fact) is the excellent price/performance ratio. All models are just a tad more expensive than your typical 2D HD TVs of the same size. This was achieved by using the patented and innovative Film Patterned Retarder (FPR) technology. FPR is a film or sorts, i.e. transparent foil with special characteristics that’s “glued” over the display during production. This foil contains a large number of microscopic “bumps” that refract light so that you get separate polarisation for each eye. Paired with LG CINEMA 3D passive polarised glasses, this produces 3D display.
The glasses in question are a story for itself. Since it’s passive technology we’re dealing with, they don’t require any sort of power - no empty battery in the middle of a film, no TV synchronisation, as is the case with active technology, no (very limiting) distance limit from the 3D TV in question… Furthermore, the glasses offer a much wider horizontal viewing angle, are exceptionally light (16 grams) and much cheaper than your usual active 3D technology for glasses.
As for the flaws of CINEMA 3D technology, we can’t say that there aren’t any, but what we can say is that those few are really inconspicuous. The first flaw is the somewhat narrower vertical viewing angle of 3D image, when synchronisation is lost. The reason for this is the FPR layer, as its image refraction method is based on horizontal viewing. Another problem is that polarisation is done in interlaced mode. One line of Full HD image is seen on the left lens of the glasses, while another one is seen on the right one. A vertical refresh rate of 100 Hz is enough to prevent flickering, however, and if you distance yourself to more than 2-3 metres from the TV (which is the normal viewing distance anyway), you’ll have a very hard time even noticing this issue. If this issue has scared you into believing that you’ll see flickering because of interlaced mode, we can assure you that you won’t notice any, because the display contains ordinary Full HD image, while the interlacing is done on the glasses themselves. This makes it somewhat unfair to dub the entire system “interlaced”, but that’s simply the easiest way to explain the way in which all of it works. Besides, active shutter glasses, despite displaying Full HD image, flicker as well, as they’re constantly “opening” and “shutting” panels in front of your eyes. In practice, all this causes CINEMA 3D to strain the eyes to a much lesser extent, enabling users to enjoy 3D for much longer.
Since this technology is cheap to manufacture, this is the first time that we have 3D TVs with potential to truly become mainstream, i.e. to become accessible to the widest auditorium.
