Kausish,
Great timing on this question, as this has been my household research
as of recent. We are in the market for a new TV as well, so I have
been reading a lot about this subject.
As far as the differences between HDTV and EDTV, let us start out just
talking about TV?s.
A normal, mid 90?s analog television runs at 525i. That stands for
525 interlaced lines on your screen changing every 1/30th of a second.
When they broadcast video information, they need to give CRT-type TVs
time to reset the electronic beam to the top of the screen so it can
get ready to paint the next sequence of lines. Therefore, they build
in an interframe gap that equals about 45 lines. There is no picture
information in this 45-line gap?it is there just to allow the TV time
to get ready to receive the next frame. Therefore, the total number of
lines in each frame is 480 + 45 = 525.
Sometimes you see this as 525i, sometimes as 480i, but to be honest,
they are both the same thing. However, you also need to be aware there
is now a digital system that has a digital interlaced 480-line format.
This is known as Standard Definition Television, or SDTV, and 480i is
the correct designation for this format.
However, this SDTV was not great on big screens. It was designed for
the smaller TV?s of the 50?s and 60?s. Not the 60? Super bowl specials
we see today. That is why on a big screen, the picture is nowhere as
clear, as say, a 19? TV.
Therefore, they came up with EDTV. EDTV removes the interlacing factor
in SDTV. Interlacing was originally used to save bandwidth, since you
only send ½ the frame at a time with an interlaced signal. However, as
technology progressed, we are now able to read media much faster, and
don?t need to save that time with the signal. Therefore, there is no
need to stay with an interlaced format.
EDTV uses a sequence called progressive scanning. It still uses 480 or
525, depending on how you want to call it, but instead of going across
with the beams, then down, they can do it all at once instead of
needing to interlace. Now, however, it is now 480p and 525p. The
problem with EDTV is that you usually need some medium that accepts
the progressive signal. Such as, (1) a video source such as a DVD
player that outputs that signal, and (2) a television or projector
that can take that signal as an input.
You can also use 480/525p with systems that still use the 480/525i.
Because the article I am going to link to can explain this better than
I can
?Here is what a line doubler (deinterlacer) does: It takes a 480-line
interlaced signal from your cable TV or VCR or laserdisc player or DVD
player and recombines the odd and even lines into a sequential
480-line progressive signal. Furthermore, when good line doublers
recombine the lines, they look for motion offsets (the jaggies), and
make adjustments to smooth them out. Therefore, their job is to
convert a 525i signal into a much cleaner 480p signal. Some of them do
this better than others, but most of them produce a much better signal
than they started with.?
As far as HDTV, it does a LOT of things. HDTV, to begin with, converts
the old 4:3 format of most TV?s to 16:9. There fore, you get a much
more theatrical look and quality to the picture. In addition, HDTV is,
in its most popular format 1080i. Therefore, we?re back to the
interlaced format, but?.2 and ½ times the lines. That?s why you get a
much clearer and sharper picture. HDTV can also come in 720p format as
well. They are working on a 1080p conversion as well, which will not
only sharpen the picture more, but also work on motion as well in the
picture.
HDTV quality though, is harder to come by the EDTV. EDTV is great, it
sharpens the picture, cuts down on jiggle, and works great with large
screen TV?s. It uses the common signal format and is less expensive
than HDTV. HDTV is still in the works. The quality really depends on
the signal you get from the channel provider. HDTV will be great I
believe, even surpassing EDTV, but give it 5 years.
As the article says:
?The funny thing is this. For the videophile who wants to spend a
great deal of money to get the best possible picture, HDTV is the
solution in theory. Nevertheless, the quality of HDTV signals will be
dependent upon a host of variables. One can expect broadcasters to
minimize production costs and save bandwidth whenever possible. There
is one thing that is certain, and that is that broadcasters have
absolutely no interest in boosting the cost of production in order to
satisfy the desires of a small contingent of videophiles. They want to
spend just enough money make picture quality acceptable to the mass
market and no more. That being the case, don't imagine that HDTV is
going to be uniformly as glorious as the pristine demos you might see
in well-calibrated retail showrooms. Just as there are variations in
picture quality today between channels, and between programs on given
channels, so will the quality of production HDTV vary as well. So the
fact is that for the mass consumer market there is not a great deal of
difference between HDTV and today's new 480p (EDTV) when it is done
right. The quality difference is certainly nothing that the majority
of the population would want to pay extra for. So the bottom line is
this--don't worry about HDTV for now. It will continue to evolve over
the next few years and it will be whatever it will be. Who cares? The
unfortunate thing is that people are sitting on the sidelines waiting
for HDTV to get serious, and they are missing out on EDTV, which is
the biggest advance in video quality since color TV.?
This article is great. In months of my own looking around, I did not
find a better source to explain all of this to a ?technological baby?
like I was when doing research at the beginning.
http://www.projectorcentral.com/video_signals.htm
Now, let?s talk about Plasma, DLP, and LCD projection.
Plasma is great, high quality, wonderful. However, and the thing the
marketing experts are not telling us, is that plasma wears out. So,
while we?re all going out and buying a wonderful product, unlike the
old fishbowl TV?s, where quality was quality, plasma can fade out over
time For example, I have a perfectly good working TV from 18 years ago
in my guest room. With plasma, no way right now that will ever happen.
Just to let you know, Any Plasma TV with a resolution of at least
1024x720 is considered HDTV compatible.
Here are some great FAQ?s about Plasma
http://www.plasmatvbuyingguide.com/plasmatv-questions/plasmatvlogevity_1.html#11145917
http://www.plasmatvscience.org/quickfaqs.html
://www.google.com/search?hl=en&ie=UTF-8&oe=UTF-8&q=plasma%20tv%20ratings%20&btnG=Google+Search
DLP was invented by someone at Texas Instruments, uses mirrors and
light to give off great color and quality. DLP is best suited for
large images. You get deeper color, esp. with blacks. There is also
DLP-A which gives a higher resolution the DLP. One of the main selling
points for DLP over plasma was for me, the fact that when a lamp in
the DLP burns out, you can replace it and your TV is as good as new
again, as where, with plasma, when it fades/burns out, you can?t do
anything about it.
Here are some great FAQ?s that explain in detail how DLP works, and
answers some common questions.
http://www.dlpsaleslab.com/faq_display.aspx
http://www.plasma.com/classroom/what_is_dlp.htm
http://www.dlptvshowcase.com/dlptv_faqs.html
://www.google.com/search?num=100&hl=en&lr=&ie=UTF-8&oe=UTF-8&safe=off&c2coff=1&q=DLP+TV+FAQ%27s&btnG=Search
LCD (liquid crystal diode) technology uses essentially a fluorescent
backlight to send light through its pixel design. LCD has to increase
the power voltage to make pixels darker. Even the best producers of
LCD technology can only produce a contrast of between 500:1 to 700:1.
Plasma has the advantage here. LCD screens claim figures between
50,000 and 75,000 hours for LCD monitors/TVs. An LCD can last as long
as the backlight (and backlight bulbs can actually be changed out). As
far as size, LCD is difficult to produce in larger sizes without pixel
defects. The largest LCD at this moment is a 40" commercial version by
NEC.
Here are some comparisons and FAQ?s on LCD for you
http://www.lcdtvbuyingguide.com/lcdtv-plasmavslcd.shtml
http://www.lcdtvbuyingguide.com.au/what_is_lcd.php
://www.google.com/search?num=100&hl=en&ie=UTF-8&oe=UTF-8&c2coff=1&safe=off&q=LCD+TV+Faqs&spell=1
Ok, now as far as digital cable signals on these TV?s. DLP will be
the best quality. You?ll get the best color and reproduction of the
picture. Not to mention it will not burn out over time, the lighting
source is replaceable.
Plasma will come second. You get great resolution and quality, but you
stand the change of dropping pixels over time and getting burn in.
LCD comes last. It has nice quality, but the size and weight knock it
down a bit. Not to mention, the color is not as good as the other two
I feel, because of the voltage issue.
As far as the best Plasma for your buck?
That?s somewhat subjective, depending on weather it will be used for
daily TV, movies, gaming, etc? Here is a list of reviews by price.
http://www.audioreview.com/Plasma-Flat,Panel,TVs/PLS_2728_913crx.aspx
Make sure you check out the NEC models.
http://www.monitoroutlet.com/999719.html
Here is reviews at eopinions.com, where you can list criteria for
reviewing the plasma TV?s
http://www.epinions.com/Flat_Panel_Televisions-Plasma
More reviews here
://www.google.com/search?hl=en&ie=UTF-8&oe=UTF-8&q=plasma%20reviews&btnG=Google+Search
Therefore, in closing, I recommend a DLP TV as your next purchase, but
plasma isn?t bad either. We chose to go with DLP, now I just have to
figure out which one for me ? You?ll have to do the same, it?s a huge
market out there right now.
If this answer requires further explanation, please request
clarification before rating it, and I'll be happy to look into this
further.
Nenna-GA
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