My head hertz, trying to understand all this tech
By Sean Captain – We’d been planning for a while to see LG’s LCD TVs at the new Alice Tully Hall in Lincoln Center, Manhattan tonight. Then we got a surprise invite to see an LCD from their compatriots and rivals, Samsung, the same day. So here’s our overview of the new Korean TV landscape.
In some ways, LG is playing catch-up to Samsung. With their new SL90, LG steps into the LED edge-lit TV world, and shrinks the set to just 1.15 inches thick–beating Samsung by a whole 0.05 inches! The SL90 seems to embody the “seamless, borderless” design move that LG execs mentioned a few times at the reception. While the screen does have a slight bezel, it’s virtually a monolithic sheet of glossy electronics. Inside, it packs a processor that doubles the frame rate to 120 per second (or 120 hertz). That automatically eliminates the stuttering look of film transferred to video and can also smooth out motion blur if you engage a feature that generates extra video frames between the originals.
This biggest challenge with edge-lit LCDs is avoiding a dark spot in the middle of the screen where the light doesn’t reach very well. Samsung has put a lot of work into this with special light guides. In the bright Lincoln Center hall, we couldn’t really judge how well the LG does. No prices have been set yet for the TVs which will sell later this year in 42- and 47-inch screen sizes
Up to 240 Hertz (maybe)
Also introduced was LG’s SL80, which will sell in August in 42-, 47-, and 55-inch models for $1,599, $1,899 and $2,799. This TV has traditional fluorescent backlighting but a hyper-fast 240-Hertz screen rate. That’s achieved partly by creating new video frames and partly by blinking the backlight—similar to opening and closing the shutter on a film projector in a movie theater.
Coincidentally (or perhaps not) Samsung had given us an earful about this a few hours earlier, saying it was a terrible idea. The reason, they claim, is that this can actually make motion blur worse in parts of the screen. You see, instead of blinking the whole backlight at once, these TVs use a “scanning backlight,” meaning they blink a row across the top of the screen, then a row below that, then another row, etc. The LG rep didn’t know how many rows the SL80 uses, but based on other LG info we’ve, we think it may be five.
The problem, says Samsung, is that with just a few fluorescent backlights that have to cover such a wide area, their light overlaps a bit; and you get strips of messy blurring across the screen where the rows meet. Samsung had shown us the effect earlier on some TV, which might have been an older LG (they hid the name). But the movie clips playing at LG’s event didn’t make it easy to see if the SL80 has that problem.
Needless to say, you can expect a continued marketing smackdown between the two companies about frame rates, image quality, and what “Hertz” really means. We’ll have to give the sets a closer look to see how well we really like them.
Samsung Loses Its Halo—And that’s Good
Meanwhile, Samsung had its own coming-out party for the 8500 series, their LED-backlit model ($3,599 for the 46-inch model, and $4,499 for the 55-inch version). In case you’re having trouble keeping track of all the tech, this type of set puts the LEDs behind the screen, instead of along the edge. The benefit here is that you can individually brighten and dim the LEDs to make some parts of the screen brighter or darker (think a full moon against a black sky).
The problem, though, is that the few dozen squares you can brighten or dim are often a lot larger than the details you want to make darker or lighter. Picture a moonless sky filed with hundreds of tiny stars. With backlit LED, you get a “halo” effect: Turning up the light behind a little star also lights up the night sky around it.
Samsung tries to fix this by using over twice as many LCDs (2,500, we think), on a screen divided into 240 blocks. That’s still not nearly as fine-grained as the two million pixels on the screen, but it allows Samsung to produce smaller halos. Did it work? A bit. It’s definitely an improvement, but at this point, they are just refining tech, not creating something radically new.
Getting rid of the halos completely would be the best. Plasma does, because it lights up each pixel individually instead of using a big backlight behind the screen. OLED, or a flat-CRT derivative called FED can also do it. “That’s why we are still waiting for OLED or FED technology, said Samsung’s engineer, Simon Lee. But we may still have to wait a little while—at least to get anything bigger than Sony’s 11-inch OLED screens. “I don’t think it’s possible next year we can launch OLED in the larger size,” Lee said—mainly because of cost.
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