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7 Questions You Must Ask Before Buying a LCD HDTV Online
1. Which Size HDTV is Right for Your Room?
With standard-definition TVs, the rule used to be that viewers would feel comfortable
watching a set from a distance of 3 to 6 times the screen size in inches.
With HDTV, the resolution is so much better that you can sit closer to a larger TV
without noticing the pixels. So with HDTVs, the rule tends to be you can sit anywhere
from 1.5 to 3 times the screen size (in inches) for the best experience.
If you know the size of the room you have already, where you want to sit, and where your new HDTV should go once you get it,
you can figure out the size HDTV you should get.
- Minimum size = Viewing distance/3
- Maximum size = Viewing distance/1.5
2. What 'Resolution' Do You Need?
In video terms, resolution refers to the amount of picture detail provided by a video signal or display.
Although you may hear references to "lines of resolution," that's mainly a holdover from the tube-TV era.
Today's digital TVs create their images using a grid of pixels; more pixels generally equals higher resolution.
This grid has a fixed number of pixels, which means if the TV receives any video signal with a different resolution,
the TV will scale that signal to fit the screen's pixels.
The picture quality you see on your TV depends on two factors: the resolution of the TV's screen and
the resolution of the video signal. Since video images are always rectangle-shaped, there is both horizontal resolution and
vertical resolution to consider.
Vertical resolution: The number of horizontal lines (or pixels) that can be resolved from the top of an image to the bottom.
(Think of hundreds of horizontal lines or dots stacked on top of one another.) The vertical resolution of the
analog NTSC TV standard is 525 lines. But some lines are used to carry other data like closed-captioning text,
test signals, etc., so we end up with about 480 lines in the final image. So, all of the
typical NTSC sources — VHS VCRs, cable and over-the-air broadcast TV (analog), non-HD digital satellite TV,
DVD players, camcorders, etc. — have vertical resolution of 480 lines. DTV (Digital Television) signals have vertical resolution
that ranges from 480 pixels for SDTV, to 720 or 1080 pixels for true HDTV. If you're comparing TVs or video sources,
vertical resolution is what's usually listed: 480p, 720p, 1080p, etc.
Horizontal resolution: The number of vertical lines (or pixels) that can be resolved from one side of an
image to the other. Horizontal resolution is a slightly trickier concept, at least for analog video, because while the
vertical resolution of all analog video sources is the same (480 lines), the horizontal resolution varies according to the source.
Some common examples: VHS VCRs (240 lines), analog TV broadcasts (330 lines), non-HDTV digital satellite TV (up to 380 lines), and
DVD players (540 lines). DTV signals have horizontal resolution that ranges from 640 pixels for SDTV, to 1280 pixels (for 720p HDTV) or
1920 pixels (for 1080i and 1080p HDTV).
Multiplying the horizontal resolution by the vertical resolution gives you the total screen resolution.
For example, a 1080p screen has 1920 horizontal pixels by 1080 vertical pixels — 1920 x 1080 = 2,073,600 pixels.
| Resolution |
Commonly called |
HDTV |
Progressive-scan? |
Wide-screen? |
Frequency |
Typical TV types |
Networks/sources |
| 1,920x1,080 |
1080p |
Yes |
Yes |
Yes |
Rare but getting more common especially in larger TVs |
Flat-panel LCD; DLP, LCD, and LCoS projection; very high-end plasma |
Blu-ray and future HD-DVD players; PlayStation 3 |
| 1,280x720 |
720p |
Yes |
Yes |
Yes |
Common in rear-projection but not flat-panels |
DLP, LCD, and LCoS projection |
ABC, Fox, ESPNHD |
| 852x480 |
480p |
No |
Yes |
Yes |
Increasingly rare |
small lcd tv |
Fox wide-screen; progressive-scan DVD players |
3. What 'Frame Rate' Do You Need?
A measure of frequency, where one Hertz equals one cycle per second.
In video, Hertz is used to describe a frame rate in frames per second.
For example, you'll often see 24-frames-per-second video at listed as "24Hz."
The rate at which frames are displayed. The frame rate for movies on film is 24 frames per second (24 fps).
Standard NTSC video has a frame rate of 30 fps (actually 60 fields per second).
The frame rate of a progressive-scan video format is twice that of an interlaced-scan format.
For example, progressive formats like 480p, 720p and 1080p provide 60 / 1080p provide 120.
4. How About Connectivity?
Connect HD digital devices like disc players, game consoles, and satellite dish components into the
2 rear connections and use the side-mounted input for cameras, camcorders, and laptops.
HDMI is the best performing interface for displaying an HD source on an HDTV.
HDMI
This implementation of the HDMI connection has been swift and common nearly to all displays labeled as HDTVs,
but not so in the computer monitors that bare resemblence. This is poised to change as PC graphics cards adopt
HDMI as the connection type and in the process become HDCP compliant. HDMI is a requirement for the adoption of
HD-DVD and Blu-Ray DVD formats, in effect an encryption system that will be used with future entertainment and home theater PCs (HTPC).
It is also important to note that HDMI is also an audio format, accompanying the HDMI video in tandem, and
plans are to expand the HDMI capability in newer versions of the controlling chip. With higher video and
audio bandwidth, it is poised to appear in nearly all A/V receivers/processors which will add some complexity to the single cable
configuration when routing sound to external home theater A/V systems. HDMI is designated to deliver multi-channel audio for both
music and video if connected through a A/V Processor with decoding capability and HDMI version 1.3
Referenced below is a some connection types that HDTV should have :
- Component Video
- S-Video
- HDMI (Digital) - High Defintion 480p/720p/1080i/1080p and *some PC connectivity
- A/V Input
5. What Is Average Rating by Customers?
If you want to buy LCD TV or everything online you should to look at average rating by customers.
For example, this website : before making a purchase, you can view comments as well as one- to five-star ratings submitted by previous buyers,
with five stars being the best. Seller ratings are displayed in bottom place on our Web site. Wherever you see a seller's nickname,
you can click 'Read more...' to view all customer reviews and rating.
6. How About delivery?
Look at the store's delivery and shipping rates before you purchase every products.
For this website:
We use the Amazon.com's delivery and shipping rates because we are amazon associate store. More detail...
7. What's The Seller's Return Policy?
Read up on the store's return policy before you even take that credit card out of your wallet.
It's good to know exactly where the point-of-no-return lies so you don't get stuck with an expensive
TV that isn't the right fit for your home and lifestyle.
For this website:
You may return new, unopened items sold and fulfilled by Amazon.com within 30 days of delivery for a full refund.
Items should be returned in their original product packaging. We'll also pay the return shipping costs if the
return is a result of our error. Just visit our online Returns Center, and we will guide you through the process and
even supply you with a return mailing label you can print out. More detail...
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