Plasma LCD 3DScreen Technical Comparison and General Information
Plasma Rental, 3D LCD Hire. A Simple Uncomplicated Generalist Review
plus a little about 3D TV.
This
short guide draws on the many comments and questions that we have bumped into
over the years when talking to our rent and hire customers. For our home page
click
Plasma LCD 3D TV Rental
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To understand 3D you have to know
that each of your eyes sees the world a little differently. Close each eye
alternately whilst looking at the same object and you will see this slight
change in the objects position. Your brain puts the two images together and
the picture in your head ends up with depth. Conventional 2D TV was filmed
through one camera lens (imagine one eye) and consequently never had depth.
3D on a flat screen is achieved
by having two lens filming from the same position, a little apart like your
eyes or, by using computers to generate the second picture that the eye
would see. Great, but two pictures have to go on one TV to give the left eye
view and, the right eye view. This is achieved in Passive screens showing
the left eye picture and the right eye picture on the screen at the same
time. The glasses you wear only show the correct picture to the correct eye. Your brain puts the two
images together and the picture in your head ends up with depth. And because
you now have depth, you have that feeling that you are actually there! The glasses are simple and light weight and can be worn
over normal glasses. |
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Stand
close to the hire screen and you will see that the picture comprises of many light
emitting dots. The dots are known as pixels and represent the screen
resolution. Important to understanding the difference between LCD and Plasma
Screens is the understanding that with Plasma, each pixel emits its own light
whereas with LCD, there is a light in the back of the screen that sends light
through the pixels. LCD is known as a back lit type screen. Hence,
Plasma offers better colour contrast as
black appears as black whereas, on a LCD screen, black appears slightly greyish
and not really as a true black as light from the back light comes through.
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Plasma is favoured for its viewing angle
and this is very relevant when used in an Exhibition environment when people may
be approaching the screen from the side. With LCD, people approaching the screen
from the side may see a faded image. With advancing LCD technology, this affect
is being reduced and most of our LCD Rental Screens are nearly as good
as our Plasma Rental Screens. |
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Any
still image displayed on the screen for a length of time will burn itself in and
appear as a ghostly image even when the picture changes. This is referred to as
burn in. Plasma screens suffer from burn in after two hours whereas LCD
screens do not suffer burn in from this until much, much later. Hence
Plasma is unsuitable for showing still images.
A
higher screen resolution equates to a sharper
picture but has a relation to the size of the screen and, the
original picture source. A low resolution on a big
screen is OK if people are viewing it from a distance and in the
case of a 42 inch screen with a 1024 x 768 resolution, we would advise 4 m / 10
foot minimum. HD (High Definition) is a description used a lot
these days and all our screens are HD ready. For Full HD the
screen has to have a resolution of at least 1080 horizontal lines i.e. a
resolution of 1920 x 1080. However, the saying, rubbish
in, rubbish out very much applies and the screen can only show what it gets. A
picture taken on a digital camera will be transferred many times - from the
camera, to flash memory, to a computer, to the internet on a server showing a
Google image, then from Google back to a PC, then onto DVD disk, then into a DVD
Player and then eventually onto an LCD Screen. At each stage
quality may suffer. And in the same way,
the quality of the DVD, the DVD Player, the length of cable to the screen and,
affect of cable connectors and junction boxes, can all have an affect. Signal
input quality can
also affect Response Time.
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Rent a TV for Sports watching?
Signal input quality can
also affect Response Time. This is how quickly a pixel can change when
showing action such as a sports event and Plasma has
a better Response Time. This is because the Plasma pixel
can change from say red to green in one pulse whereas an LCD pixel goes
from red to inactive, to green.
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Also,
old programs such as Microsoft PowerPoint 2003 were
not designed for wide screens. Plasma and LCD screens have a
ratio of 16 to 9 - imagine units length to units height. Old
programs were designed for old displays with a ratio of 4 to 3. Now,
Plasma and LCD Screens can compensate to avoid the short and fat affect
(see the pictures), from stretching a 4:3 image to 16:9 but. you may lose the extreme edges of the
image or not be able to fully utilise the Plasma LCD screen. This unused area
gives what is known as the letter box affect. The latest version of
PowerPoint (2007) and professionals, take care of this for you.
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Neither Plasma or LCD Screens are suitable in sunlit
areas as they do not emit enough light to counteract the effects of
glass reflection and direct sunlight. For these circumstances you need a
sunlight readable screen. (We do not hire these.)
For
much more technical information visit
Wikipedia on LCD
and Wikipedia on
Plasma Displays and
Wikipedia on
3D TV
For help contact
John on 020 8397
0197, 07957 972595 -We
rent to private individuals and
companies, in London and north Surrey and southern England.
Q7db Limited rents Plasma 3D LCD TV Screens to London, Home Counties and
Exhibition Centres at Birmingham NEC, Earls Court, Olympia and Excel
