Posts tagged ‘hdtv’
The White Dashes at the Top of a TV Picture
By Chad Upton | Editor
They may appear as rapidly flashing dots, dashes, lines or boxes across the top of your TV screen.
The white lines are more prevalent on HDTVs, although they can show on older standard definition sets too.
They often appear while watching an HD channel that is broadcasting a standard definition signal, which frequently happens during commercial breaks and shows that are not available in high definition.
The lines are supposed to be there, you’re just not supposed to see them. If you have seen them, they will vary in size and shape depending on your TV.
These lines are like barcodes embedded in the picture. Closed captioning, teletext and programming guide information is represented by these white lines. Your TV can interpret them and display the information in a format that you can read.
Although this primarily affects HDTVs, it stems from variances in old Tube TVs (Cathode Ray Tubes). In the early days of television, there were extreme variances in production of television sets — some would cut off more of the picture than others.
Broadcasters overcame this problem by trying to keep all titles and important actions away from the very edges of the screen, in case they were cut off on some TVs. That extra space that you don’t see is called the overscanned image (because of the way that CRTs would paint an image on the screen by scanning side to side sixty times per second).
The overscan area became a good place to hide extra information when closed captioning data was added to TV signals.
HDTV signals do not overscan. Their signals are newer and were designed to encapsulate extra information from the beginning. But, you may still see these lines on an HDTV if the broadcaster is showing content that has the lines.
Most good televisions have the option to adjust overscan, including hdtvs. You’ll have to consult your manual, but this option will allow you to adjust the picture so the white lines are not visible.
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3D TVs are Available Now
I was at my local big-box electronics store on the weekend where they had a 55″ Samsung 3D TV running. The picture looked funny to me, but one of the other customers, who I suspect had been sitting there for a while, immediately handed over his 3D glasses and told me to try it out. It was awesome.
It was the kind of experience that was once limited to theme parks and special events.
3D media in general is not new; the first 3D camera was patented in the year 1900. Many early prints and movies used red/blue glasses to present 3D images. This technique is called Anaglyph. The color filters are a basic way to present separate images to both your eyes from a single frame, which gives you the perception that some objects are closer than others. The downside is that everything is either red or blue.
I remember Captain EO at Disneyland back in the 80s, that was the first 3D film I saw without the red/blue lenses (although they were invented in the 1950s). In most cases, theaters use glasses with polarized clear lenses. The polarized lenses are different, each one filters out light waves that do not oscillate in the same orientation as the polarization. The projection system projects two images, one that will be filtered out by right lens and one for the left. This allows us to have a full color 3D experience. Although the projection system is very expensive, polarized glasses are fairly cheap and that’s why they’re the primary choice for theaters.
In 2003, 3D films started gaining in popularity, showing up in regular and IMAX theaters. Now, many local theaters have at least one 3D projection system. Some of the films in this time have included: Bugs! (2003), The Polar Express (2004), Chicken Little (2005), Nightmare Before Christmas (2006), Beowulf (2007), Meet the Robinsons (2007), Bolt (2008), Coraline (2009), Up (2009) and of course Avatar (2009).
There were many more, but those are some of the more popular ones. Since there have been so many 3D movies in the theaters, 3D home theater will let you enjoy those movies in all their glory over and over again. (more…)
You Can Easily Buy Tamper Proof Screwdrivers
I have a long history of taking things apart; as a Child I had a reputation for never putting them back together. There is some truth to that, but somethings are more fun in pieces.
Before I understood how they worked, I saw things as magic boxes. I wanted to know how the engineers solved all of the problems that made the product useful; what were their secrets?
As an adult, I still like taking things apart. Sometimes, I want to know how it works; other times it doesn’t work and I want to fix it, or break it further.
Unfortunately, it’s not always easy to disassemble things.
If you’re like me, you’ve probably tried to disassemble something and then realize you don’t own a screwdriver that can turn a triangular notched screw-head. Or, maybe you have noticed funny looking screw-heads in public restrooms. Not the people, the metal screws used on fixtures and cubical walls. If you don’t recognize the pattern on the screw-head, they’re likely what we call “tamper proof” screws. (more…)
How to Get Free HDTV Channels
When I say free, I don’t mean free with your paid cable or satellite package. I mean 100% free without paying for any service.
When television broadcasting began in North America, the broadcasts were completely free. The costs associated with producing TV were covered by program sponsors (advertisers). TV signals were received over the air, so all you needed was a television and an antenna (aka “rabbit ears”). This worked great at the time because TV was new and nobody knew if it was going to be successful; laying cable to distribute signals didn’t make any sense and satellites weren’t an option yet.
Once television was a proven success, viewers wanted more content on bigger and better televisions. Today, those demands haven’t changed, but the technology has.
Receiving signals over the air was not perfect, there were a limited number of channels that could fit in the airwaves. Reception was spotty, but Cable and Satellite services came along with more channels and reliable signals that didn’t require any adjustments.
The technology has changed again. The development of digital signals has allowed broadcasters to fit many channels in the same space that used to only fit one channel. Although it caused a lot of disruptions in June of 2009, the United States ceased all analog TV signals within a specific frequency range. That means the once crowded airwaves are much more useful with digital signals that can stuff more channels in the same space.
Some broadcasters have been distributing their television signal over-the-air for more than 50 years and they continue to do so, now in digital. The secret to picking up these free channels: rabbit ears.
Seriously.
To many people, this will sound like a huge step back, and in some ways it is. You’re not going to find John and Kate or Jersey Shore on the free channels, but it could be worse: you might find John and Kate or Jersey Shore on the free channels.
If you’re on a budget; or you only watch the most popular network shows; or you want to stick it to the cable-man; or you want to pickup really good HD signals on a TV without a cable box or satellite receiver, then this is an option to consider. In many cases, digital over-the-air signal quality rivals cable and satellite signals, where signals are highly compressed because of bandwidth limitations.
Digital rabbit ears are much better than the coat hangers of the past — if you’ve upgrade to a digital cordless phone in the past couple years, you’ll understand the difference in reception, reliability and clarity that digital signals offer.
Depending on where you live, your channel selection will vary. In some places, you can get 10+ HD channels and dozens of standard digital channels, all for FREE! If you live in the United States, you can enter your zipcode in AntennaWeb’s search engine to see a list of the channels you should receive. In many places, you should get most (or all) of your favorite prime time shows in free HD. All you need is an HDTV, an ATSC tuner (most HDTVs have one built in) and an antenna. Here are some examples of affordable indoor and outdoor antennas that you can buy.
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