Posts Tagged ‘Plasma’

Samsung and Panasonic 3D TVs: Any better than Sony?

This past Sunday, I packed up my Sanyo Xacti pistol camera and headed over to a nearby Best Buy store. My goal was to re-run the same off-axis viewing tests that I conducted on a Sony Bravia 3D LCD TV at the CEA Line Shows. Except this time around, my guinea pigs would be Samsung and Panasonic products.

I picked a normal exposure for the correct (level) view and didn’t change it as I rotated the camera and glasses around. This was done so you could see any change in screen brightness.

First up was a Samsung 55-inch LED model. I settled in the comfy chair, pulled out the lone pair of active shutter glasses, and picked a few scenes from Monsters vs. Aliens.

Figure 1 shows a close-up view of the screen through the right eye lens, with the glasses positioned at the correct angle to the screen. No ghost images (crosstalk) were spotted and picture quality was high.

Figure 1

The next image shows the view with the glasses tilted about 30 degrees to the left. No objectionable ghosting here, either, although this particular scene is of a TV weatherman on a ‘flat’ picture tube – not much 3D going on here.

Figure 2

Figure 3 shows the view with the glasses tilted about 60 degrees to the left. The image is noticeably darker now, as the polarizers in the glasses are starting to cancel out the polarized light from the LCD TV screen.

Figure 3

Figure 4 shows – nothing! The glasses are tilted about 80 degrees to the left and the ‘twist’ of polarized light from the LCD screen is canceled out by the polarizing angle of the 3D glasses. Not surprising, considering that two polarizers are being used in the 3D glasses.

Figure 4

These tests don’t mean the Samsung glasses are completely free from ghost images when tilted. Figures 5a and 5b show two different views with the glasses tilted at about 45 degrees to either side, and you can see crosstalk in both images.

Figure 5a

Figure 5b

On to Panasonic! Figure 6 shows the 50-inch plasma screen head-on, as seen through the right lens.

Figure 6

The next figure shows the same screen with a tilt of about 45 degrees. Picture brightness has dropped a little, but there is no ghosting evident in the image.

Figure 7

Figure 8 shows the screen as seen at a nearly vertical angle, about 80 degrees. Image brightness is still good and there is only a hint of ghosting to be seen (look around St. Peter’s dome). Figure 9 shows the screen 90 degrees to horizontal and it’s still largely free of crosstalk.

Figure 8

Figure 9

From these tests. it should be pretty clear that plasma has a big advantage over LCD technology for viewing 3D, and that’s because plasma TVs don’t use polarizers as part of their imaging process. (Anti-glare glass is used, but doesn’t seem to have an adverse effect on 3D viewing angles.)

In contrast, it’s a tricky proposition to pair up polarized glasses with a polarized TV screen, as we’re just seen with Samsung and Sony LCD TVs. Your head really needs to be level to avoid seeing any ghost images.

It appears that the crosstalk problem is worse on Sony’s 3D LCD TVs because they’re only using one polarizer per glass lens (that’s the consensus educated guess). That decision results in images that are brighter, but are ridden with crosstalk – even when the glasses are positioned level to the screen. So there’s no allowance for head tilt  – even slight amounts – with Sony’s approach.

By using two polarizers per lens, Samsung cuts down crosstalk more thoroughly, just at the cost of screen brightness. But you can tilt your head at a greater angle and not be distracted by crosstalk through the glasses.

Panasonic is also using dual polarizers and their images were about as bright as Samsung’s, but nearly free of ghost images when viewed at any angle. If and when OLED-based 3D TVs make it to market, you can expect to see that same level of performance.

So…now you know!

3D TVs: Not Selling like Hotcakes?

Thinking about buying a 3D TV? You might be wise to sit on your hands for a while longer, because you’ll save a few hundred dollars and get more equipment at the checkout line to show for your patience.

Sunday’s Best Buy insert showed a Panasonic 3D TV package that includes the TC-P50VT20 3D plasma TV (comes with one pair of glasses, PLUS an extra two pairs of active shutter glasses, PLUS Geek Squad delivery and setup, all for $2249.96. That supposedly reflects a $700 savings over full list price. (The extra two pairs of glasses are valued at $300).

A few months ago, Panasonic announced a 3D bundle of the TC-P50VT20, one pair of glasses, and their BDT-300 3D Blu-ray player ($399.00) for $2,899, exclusively at Best Buy. That package likely ran out of gas quickly because there are only a handful of 3D Blu-ray discs available to watch right now.

So Best Buy’s new deal shifts focus to ESPN’s 3D coverage of the World Cup soccer matches, which started on June 11. All fine and dandy, but the ‘catch’ is that some cable TV customers will have to upgrade to newer Samsung, Pace, Motorola, and Cisco set-top boxes to receive the ESPN 3D channel – it can’t be done on older set-tops. (And good luck finding out exactly where and if ESPN 3D pops up in your service area!) UPDATE: Comcast is carrying the ESPN 3D signal in the 1080i side-by-side format, encoded as MPEG2 @ 18 Mb/s.

Samsung and Best Buy may have put together an even better deal. For $2769, you can get a UN55C7000 55-inch 240Hz LCD TV (LED backlit, of course) PLUS a BD-C6900 Blu-ray player, PLUS a 3D starter kit (two pairs of AS glasses and a copy of Monsters vs. Aliens in 3D), PLUS the Geek Squad delivery and setup as before. Don’t need a 55-inch screen? Substitute a UN40C7000 40-inch LCD 3D TV, and the price drops to $1799.

The 3D ‘kit’ is all yours for about $2800 bucks.

‘New kid on the block’ HH Gregg (at least, new in eastern Pennsylvania) has the same deal on the 55-inch set, or you can go with a 46-inch model for $2139. (They don’t mention anything about installation and setup, though.) Sixth Avenue Electronics also has the 55-inch and 46-inch packages, and will do free delivery and installation on both.

The Sears Sunday flier states that you can get the BD-C6900 BD player and the 3D starter kit free with the purchase of any Samsung 3D TV, which might be the best deal of all. They’ve priced the 46-inch LN46C750 3D TV (CCFL backlight) at $1529, while Samsung’s PN-50C7000 3D plasma TV is tagged at $1799.

Imagine that. We’re barely three months from all those big 3D product launches in New York, and prices have already started dropping like a stone. To make matters even more interesting, XpanD announced a few months ago at the NAB show that they plan to introduce universal ‘learning’ active shutter glasses to the marketplace later this year, which will directly impact the sales of proprietary AS glasses.

These bundled prices make you wonder about the real value of the glasses and Blu-ray players. In a business where margins are very tight, accessories such as glasses, cables, and even installation services are very important to the bottom line. Both the Panasonic and Samsung BD players list for $400, but my guess is that neither is selling very well right now: Hence, Panasonic’s decision to de-emphasize the player and Samsung’s ploy to throw theirs in as an extra to drive TV sales.

What will be telling is how much this year’s World Cup 3D coverage drives TV sales. You may recall that the World Cup did little or nothing to stimulate sales of HDTVs four years ago because Asian TV manufacturers overlooked an obvious fact: World Cup fanatics in Europe prefer to watch matches in pubs and taverns with their pals – not at home.

While ESPN is to be commended for making a substantial effort and investment to produce 3D coverage, it’s unfortunate that one of the least-appealing sports to Americans (historically speaking) is the focus of this coverage and not something like baseball, or basketball (NBA Finals), or even tennis.

What happens after July 11, when the Cup tournament concludes? How much 3D coverage will be available to drive TV sales throughout the summer?

Apparently not very much, based on the announcements made to date. And that means we’re likely to see even bigger discounts on 3D TV packages by September.

(By the way, none of the package deals I mentioned includes an HDMI cable. Hey, retailers have to make a buck someplace!)

?

HDTV Tech Talk Tutorial: 3D Program Formats

Here’s a quick tutorial on 3D program and transport formats, all coming to a TV near you.

Have you heard enough about 3D yet?

Probably not. Samsung and Panasonic are long out of the gate, while LG just started its advertising campaign for INFINIA LCD TVs during the NCAA Men’s Basketball Tournament.  And there will be more companies following with 3D TVs, Blu-ray players, and a host of accessories.

One question I’ve gotten repeatedly is this: “How do they pack a 3D signal into a conventional cable TV channel?” Another one: “How can DirecTV send out 3D, which is progressive scan? They’re not broadcasting in 1080p!”

Time to wheel out the whiteboard! In a nutshell, here’s how the different 3D transmission formats work.

THE DETAILS

Earlier this month, the 3D amendments for the HDMI 1.4 standard were released. These standards include a host of broadcast 3D formats, along with the Blu-ray top/bottom packed 1080p frame format. (I’ll touch on that, too.) These mandatory 3D formats must be supported if the HDMI interface is a ‘true’ 3D connection.

That’s not to say that a TV manufacturer won’t support other formats: They can, and they are! Examples of ‘other formats’ include checkerboard, interlaced 3D, line-by-line, and alternate frame. There are even 2D+ depth and other ‘overlay’ formats (think of the FM subcarrier for stereo from the 1950s) that are backwards-compatible with older TVs.

What we’re interested in is what DirecTV, Dish, Comcast, Cox, Discovery, and possibly major TV networks like CBS, NBC, and Fox are doing, and might do. Here’s the short list:

Side by side: This is the format that DirecTV will launch in June. It’s also likely to be used by Comcast, Dish, Cox, and any other multi-channel video system. In the side-by-side system, the left eye and right eye images are anamorphically squeezed to fit into a single 1920x1080i/30 frame. (Figure 1)

Figure 1. The side-by-side (2x 960×1080) 3D format. Image copyright ©2010 DirecTV. All rights reserved.

That means that each image has half the horizontal resolution, or 960×1080 pixels, when expanded back to its normal shape and presented sequentially. Does this look bad? Not really, considering there’s still over 1 million pixels in each eye. As it turns out, HDMI 1.4a calls for side-by-side exclusively with 1920x1080i video content.

Top + Bottom: This format is more likely to be used by stations transmitting progressive scan signals. Once again, the left and right eye images are anamorphically squeezed and packed into a single frame, except they are aligned one atop the other. This is the standard for 1280x720p/60 and 1920x1080p/24 transmissions. (Figure 2)

Figure 2. The top + bottom 3D transport format. Image copyright ©2010 DreamWorks Animation. All rights reserved.

In this case, each image has half the vertical resolution of a full HD video frame. For a 1080p program, that’s no big deal – each eye works out to 1920×540 pixels. But 720p comes up short, with an effective resolution of 1280×360 pixels in each eye.

The thinking here is that it’s better to sacrifice vertical resolution in a progressive scan TV system than horizontal resolution. I don’t think it makes much of a difference with 1080p content, but 720p? It may not look as good as it should.

What about the alternative? Using a side-by-side format, this would reduce the resolution of each left and right eye image to 640×720 pixels – not much more than a regular DVD. As a result, adopting 720p as an HD format may leave something to be desired with respect to 3D.

HDMI 1.4a: There are two formats here. One uses a top/bottom dual-frame structure (Figure 3) with a total of 1920×2205 pixels. (45 pixels are a blanking or metadata interval.) This retains full 1080p resolution and the frame rate is 24 (23.98) Hz. The other format is for video games, and oddly enough, it’s at a lower resolution – 1280×720 pixels, with either a 50Hz or 60 (59.94) Hz refresh. (Figure 3)

Figure 3. The HDMI 1.4 Blu-ray frame packing structure.

To summarize, these are the ‘mandatory’ HDMI 1.4a 3D formats. A compatible 3D TV will support all of them. On the other hand, set-top boxes and media players only have to provide one of these signals (for Blu-ray players, it’s the full 1080p top + bottom format exclusively), based on the content being served up.

It’s important to remember that, not matter what delivery (transport) format is used, the 3D TV will present ALL of these as sequential left eye/right eye images, using the same active shutter glasses. Only the physical resolution of the images will vary, along with frame rates.

And now you know the rest of the story…to quote the late, great Paul Harvey.

Game On! Early tests of 3D plasma vs. 3D LCD

Consumer Reports has posted a short video clip that shows their preliminary tests of Panasonic 3D plasma and Samsung 3D LCD TVs. You can find it here.

http://www.consumerreports.org/cro/video-hub/electronics/televisions/16935238001/

During the clip, they point out that while both technologies exhibit high contrast 3D images, the Samsung images essentially go black if the viewer lays down while watching TV with 3D glasses. (This puts the polarization axis of the glasses at 90 degrees to the screen, and is not recommended in any case!)

Performing the same test with the Panasonic plasma resulted in a slightly dimmer image, and nothing more.

There’s an easy explanation as to why this happens with LCD TVs. Liquid crystals can only shutter light that is already polarized, which is why each LC pixel element has two polarizers – one mounted at the rear of the pixel wall, and one at the front. Rotating a pair of active shutter glasses 90 degrees in front of the screen in effect acts as a third light shutter and cancels out whatever light remains after the LC imaging process.

Ever hold two pairs of polarized sunglasses at right angles to each other? Then you’ve seen the same effect.

Now, let me state that lying down on your side while watching 3D is a pretty dumb idea all around. The images are oriented in the wrong axis with respect to your vision, and it’s also got to be uncomfortable!(Come on, how lazy can one get?)

Even so, this video demonstrates clearly that moderate changes in polarization angles make images from 3D LCD TVs noticeably darker, so if you tilt your head to one side or the other while wearing glasses and watching a 3D LCD TV, you will experience this effect.

Why doesn’t this happen with plasma? Because it doesn’t use polarized light, just a burst of light from color phosphors. OLED 3D TVs (if and when they ever get here) are also free from this cross-polarization problem.

This is another example of why 3D TV needs to be thoroughly explained to potential buyers so that they don’t run into any unpleasant surprises after the sale.

Samsung, Panasonic Get a Flying Start on 3D

This past Tuesday and Wednesday, Samsung and Panasonic showed they’re serious about marketing and selling 3D TVs in the United States with some significant product announcements.

Samsung’s press event, held at the Samsung Experience in the Time Warner Center, showcased numerous demos of 3D plasma and LCD TVs.  Content from 3D Blu-ray discs and DirecTV was featured, and DreamWorks Animation head Jeffrey Katzenberg even stopped by to add his two cents to the proceedings, attracting a crowd of paparazzi along the way.

In the LCD line, the LN46C750 (CCFL) will be first out of the gate with 3D support and 240Hz image processing. It is expected to retail for $1q,700 and will be in stores in May. Over in the LED BL LCD line, eight models ranging in size from 40 to 55 inches will handle 3D playback, starting with the $1,999 UN40C7000 and topping out with the 55-inch UN55C9000.  Look for shipments to start in March with selected models.

Here’s the UN46C9000 in action, showing 3D content from DirecTV.

Plasma is still part of the 3D equation at Samsung, and six new PDP TVs are ready to deliver 3D. The 63-inch PN63C8000 sits at the top of the line and will set you back $3,800 (May 2010), while the 50-inch PN-50C7000 can be yours fro just $1,800 (also May 2010).

Got Blu-ray? The BD-C6900 is BD3D compatible and ready to deliver the goods (which is a neat trick, considering that Silicon Image just finalized the HDMI 1.4 delivery formats last week!) for $399. It should show up later this month. Each 3DTV and the Blu-ray player will  come with one pair of active shutter glasses. (Samsung is also running a limited-time promotion with two pairs of glasses and a 3D BD copy of Monsters Vs. Aliens with each new TV.)

On Wednesday, Panasonic unveiled its first 3D TV entry, the 50-inch TC-V50PT20 ($2,499). This set will come with one pair of active shutter glasses.  Larger models will be rolled out as the year progresses, and there aren’t any plans currently for 42-inch or 46-inch 3D models. (No surprise, considering how inexpensive 50-inch glass has become!)

There’s also a new Blu-ray player, the BDT-300. It will retail for $399 at Best Buy. Want the TV, player, and glasses? You can have the lot for $2,900.

It should be noted that plasma TVs have always had the ability to switch at the high speeds required for 3D (120 Hz)..they just haven’t had the correct interface and HDMI 1.4 support. LCD TVs that process at 240Hz can also juggle a 3D signal nicely. (For that matter, so can 120 Hz sets, but the faster refresh rate does a cleaner job with motion detail.)

It’s possible that many of these sets will be purchased and not used for 3D viewing right away, as consumers want to “future-proof” themselves. Considering how few Blu-ray players are on the market, it’s probably not a bad idea to wait a few months until more product is on the shelves and the market figures out pricing.

Here’s an actual side-by-side 1080i video frame from DirecTV.

As for DBS and cable-delivered 3D, you’ll need an upgraded set-top box with HDMI 1.4 support to view the side-by-side 3D content that most networks are likely to use. DirecTV has already stated its intention to use side-by-side, while ESPN is still in the planning stages.

Keep in mind that both side-by-side and top/bottom 3D delivery formats cut resolution in half. Side by side slices horizontal resolution, while top/bottom pares vertical resolution. For a 1080i image, that means 960×1080 pixels in each eye, while the 720p format gets whacked down to 640×720 pixels per eye…not much better than a DVD.

In contrast, the Blu-ray format delivers two complete 1920×1080 progressive frames (left eye on top, and right eye below) with a blanking interval of about 40 – 45 pixels. So you can expect 3D content from Blu-ray to look much better than network content.