Quote Originally Posted by Woochifer
Does that issue also affect the edge-lit LED LCDs?

I know that the haloing occurs with the sequential local dimming LED models, and with certain types of images (like starfield backgrounds), the objects get obscured altogether because the processor interprets those low level images as completely dark.
It does not effect edge lit, just local dimming models. The best test I could find that really showcased the problem was Star Trek Generations. There are several scenes of space with both bright stars and dimmer ones. On the Cell based Sony XBRpro (which uses The “Triluminos” full-array LED backlight local dimming but with thousands more LED lights) the stars are perfectly rendered with a perfect delineation of bright and dimmer stars. On the top of the line 55" Samsung (another LED backlit with fewer LED's), the bright stars are very dim, and the dimmer stars non existent. Another occurrence of the weakness of the new LED backlit Samsung's is when you have a completely dark background, with a bright section anywhere on the panel. There are halo's around the bright areas that are very noticeable, instead of just rendering the white spot in the black background.

Since the local dimming is based on APL, the Samsung television's processing dimmed brighter stars, and eliminated the dimmer ones altogether. On the XBRpro, the Cell based video processing and the additional LED lights captures the scene perferctly. I do not think it is the LED technology itself that causes the problem, I think they just need to add more backlit LED's to the panel, and more individual control of those lights. I think the Samsung uses about 1,000 white LED arranged in rows that cover the panel. The Samsung controls their backlighting in blocks of 10 LED's. The XBRpro uses close to 6,000 LED lights arranged in cluster of four with three colors, two green, one red and one blue. Instead of controlling the lights in groups, the XBR controls the clusters individually, which mean deep darker blacks (Kuros blacks), no halos, and a much wider color gamut than Samsung can achieve.

Edge lit panels can perceptively increase the contrast, but it also limits the viewing angle that one can watch. If you have two people sitting close together, it is not likely they will see the same contrast or color from their individual seating positions.