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Big Screen Computer Displays
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.(1999) There are many kinds of big screen high
resolution displays that are very useful for Home Theater Computers. Remember we are
talking about VGA/RGB and not S-Video. That is, you're directly connecting the computer by
its VGA output directly to the display. That means, no puny "TV-Out"
which downconverts computer graphics to television compatible video signals.
For proper justice to a Home Theater Computer, you
need a high resolution display that can accept VGA/RGB.
CRT Projectors
Basically, most of them act like huge multisync computer monitors.
They usuallly have 5 BNC inputs, the same number as a high end professional desktop
computer monitor. You just use the same computer monitor cable that is used with these
professional monitors. One of the most important considerations after knowing the
capabilities of the CRT projector (ie 'can sync up to 135Khz' for an NEC XG135 - my CRT
projector) is to know the size of the tubes used in the CRT projector.
Picture 1: NEC XG135 CRT Projector
A 7 inch CRT projector will produce a picture about as sharp as a 14 inch computer
monitor, in terms of pixel sharpness for equivalent resolution. (ie, basically it looks as
sharp as a 14 inch computer monitor enlarged to wall size proportions). An 8 inch CRT
projector will look about as sharp as a 17 inch computer monitor. I can attest to you that
1152x864 looks sharp and wonderful on an NEC XG135; just like 1152x864 has been the
favourite resolution of choice for 17 inch computer monitors. A 9 inch CRT projector will
be about as sharp as a 19 inch or 21 inch computer monitor and be able to do a decent
1280x1024 or 1600x1200 image.
They are heavy and must use fixed installations - and they require extensive
recalibration if you move around the CRT projector. Apart from their usual heavy 100-200
pound weight and difficult setup, one the main disadvantage of CRT projectors are that
they are pretty expensive for good models. Though you can get a really good refurbished 8
incher with 0 hours on the tubes for just about $5000 to $9,000 if you look around
carefully.
Avoid 'video grade' projectors as they can only do 15Khz - TV quality. 'data grade'
projectors can display up to 640x480. The most common type, 'graphics grade', can display
1280x1024 or higher. That is the type of projector you should look for - only buy data
grade if very cheap (like $500 or $1000 for a fully working model with no burn-in
problems). When buying a CRT projector, be very careful about checking for burn-in
problems. If you are familiar with old arcade machine cabinets, you will notice burn in
sometimes - like an old darkened Ms. Pacman maze image burnt into an arcade machine screen
that has been turned off. The same type of phenomenon afflicts CRT projectors if they are
kept displaying the same image for a long time.
They almost all have picture size/position/pincushion/trapezoid/etc controls just like
a computer monitor, but has over 10 times more control such as
linearity/linear-balance/point/white balance/etc .... You will be overwhelmed at first.
Don't forget mechanical focussing and alignment of 3 lens so they are easier to converge
electronically. It takes all day just to set up a CRT projector - and sometimes takes the
next day as well. But if you can (and like to) adjust a computer monitor to perfection
with an image that fills up the bezels perfectly, you can easily learn how to do the same
for a CRT projector.
Even though CRT projectors are slowly becoming an obsolete technology, CRT projectors
will likely be stay as a niche product indefinitely because they are the only way to do
good 3D simulations as well as other low-persistence applications which requires the
display to flicker rather than shine continuously (as LCD/DLP/DILA projectors often do).
CRT tends to be superior when you're a framerate maniac who insist on 60 frames per second
perfect fluidity in arcade style video games.
I own an NEC XG135 MultiSync CRT projector - the same one pictured above. It's 100%
MultiSync and syncs up to 160Hz vertical refresh and 135Hz horizontal refresh. It supports
almost any reasonable aspect ratio via the use of picture sizing controls - to invent 4:3
and 16:9 aspect ratios. It has the bandwidth to display 1024x768 and 1280x720 at a full
120Hz refresh. It is able to sync to 1920x1080p (non-interlaced) although it gets a bit
fuzzy, like trying to display 1600x1200 on a 17 inch computer monitor.
My projector is 139 pounds and is about 3 feet by 2.5 feet by 1.2 feet, and projects a
92 inch 16:9 image of 1280x720 resolution on my projector screen. Yep - a widescreen
Windows desktop.
I sit only 8 feet away from this display - even though it's much bigger than a TV set.
You usually sit only 1.5 times screen width away from a computer monitor, so you should do
the same for your big screen computer display as long as they are sharp enough. DVD images
actually look like film so sitting this close is not a problem for DVD. However, this
makes TV quite a bit fuzzy looking - although acceptable looking, I don't watch much TV in
the first place anyway. Just imagine sitting only 1.5 times screen width from your current
TV set. Yuck, you think? On my setup, it is actually bearable because the
flickering/interlacing is eliminated by using a computer TV tune card or by using a
doubler/scaler. Though if you plan to watch a lot of TV via a doubler/scaler/computer, I
recommend 2.0 times screen width. (Much closer than with a regular TV, but it will make
the detail of DVD really show up much better too!)
Don't forget you do need to turn off the lights before watching a picture on the
projector, for best results.
Digital Projectors
You probably know these as the common garden-variety conference room computer
projectors. Many support 640x480, 800x600, 1024x768 or 1280x1024.
Picture 2: Kodak DP850 DLP projector
Some of these are not very good for home theater because they are optimized for
conference room, but some projectors actually are good. Most videophiles still think that
CRT projectors are superior, but there are a few amazing digital models that are starting
to break that notion. In the next few years, digital may be the only way to go especially
as manufacturers stop making CRT projectors, some of which are considering stopping making
the huge hulking beasts.
Technologies of digital projectors include LCD, DLP and DILA. LCD and DLP are getting
pretty common in corporations for conference room use, and are also getting very popular
among projector users.
They have a fixed pixel array so it is always recommended to display source that is the
same resolution as the pixel array. That means a good scaler or a Home Theater Computer is
ideal - they can be made to display a computer resolution matching the digital projector.
DVD playback can look great this way.
One example is the Davis DL450 which appears to have originally been aimed at
conference rooms but turns out to be a wonderful DLP projector that is said to almost
outperforms some 7 inch CRT projectors dispite its limitation of only 800x600. Just look
at rave reviews (including Alan Gouger) of the Davis DL450, for example.
Some of the best digital projectors are DILA projectors like the Hughes JVC G1000 DILA
projector. They can produce INCREDIBLY sharp images, provided you are outputting the same
resolution as the DILA. The G1000 is an unusual 1365x1024 resolution which is easily
matched only by a Matrox G400 or GeForce256 coupled with PowerStrip - that way, you can
make a computer output a resolution that makes computer text literally 'jump off the
screen' with the G1000. This projector is very expensive, however, but is the model that I
would currently recommend if you were thinking of using a digital projector in its price
range.
Huge advantages of digital projectors include their light weight (usually 10 pounds),
portability, easy setup (just set it up and turn it on - no hours of pain like for a CRT
projector).
Bear in the mind of disadvantages as well, such as very terrible picture quality of
cheap and old models. Picture quality varies quite a LOT between digital models, ranging
from truly dim and pitful, all the way up to dazzingly sharp and bright. Be
careful about screendoor effect - if you sit too close to a projected image from a digital
projector, you will see the pixels as if you're looking outdoors to your backyard through
a screen door. If you want to sit close, make sure you get a really, really high
resolution digital projector. The minimum resolution I recommend is 1024x768 with the
exception of the DL450 - the DL450 is so good, it's sometimes worth going down to 800x600.
The fact is, many people prefer the DL450 picture over most 1024x768 digital projectors,
even when playing DVD (Amazing but true)! Many people are still looking for the holy grail
- a cheap 1024x768 DLP projector that has a picture that is as natural looking as the
Davis DL450.
Also, the Kodak DP850 is a clone of the DL450 - so do not be surprised if the DL450
looks identical to the photo above. The DreamVision is also a fancy clone of the DL450
too.
Don't forget you still need to turn the lights off (or at least dim them very
drastically), if you want to use a projector, regardless of what type of projector it is.
Big Screen CRT Computer Monitors
Almost all of them looks like an ordinary TV set, with one exception: They are designed
to display higher resolutions.
They tend to be bulky and just as heavy as a TV set of the same size. They are easy to
setup and behave like a computer monitor with the same digital picture adjustments -
sometimes you can do the computer-monitor-style picture adjustments by remote control.
One thing to keep in mind, that many of these sets use the same TV tubes used in
regular TV sets. As a result, the dot pitch tends to be quite coarse, usually 0.8 to 0.9mm
although some of the more expensive models use custom 0.6mm dot pitch tubes. Therefore,
most of the 27" to 32" displays look good at 640x480 but no higher. Some of the
bigger displays like the 16:9 models or the large sizes like 36", look pretty good at
800x600.
Another disadvantage of treating these CRT's like a computer monitor in a living room
is that you don't sit close to them. You usually sit only 1.5 times screen width away from
a computer monitor, but often a TV is put all the way to the end of the other room. As a
result, you're squinting just to try to use only 640x480 even if it is very sharp. Be
careful to account for viewing distance considerations if planning on getting a big screen
computer monitor. Even though I strongly recommend sitting closer to a computer
monitor than to a television set, I also do not recommend sitting as close as only 1.5
times screen width away because of the coarse dot pitch; you will see the phosphor matrix
if you sit this close. My recommendation about 2.0 times screen width (and up to 2.5) for
big screen computer monitors, which is an excellent compromise. As a result, get the
biggest size you can afford. My recommendation is the RCA MM36100 which is a 36 inch
computer monitor/TV/HDTV all in one unit - and has a superior picture to any past big
screen computer monitors I've seen, including NetTV, Gateway Destination, Arcadia, etc.
Picture 3: RCA MM36100 36" computer monitor/HDTV
Some of them actually are CRT-based HDTV sets with the ability to double as computer
monitors as well. They are simply TV's that just has a VGA jack added to the back of them,
while other big screen computer monitors do not even have a TV tuner.
The displays tend to be expensive, but you may be surprised to learn that they are much
cheaper than most HDTV sets. For example, the RCA MM36100 36 inch computer monitor is only
$2000 street, which makes it a good deal for people who cannot afford a projector or for
people who has a bright living room room. You can read more
specs about RCA MM36100 here.
Other popular brands include Princeton Graphics (which makes GREAT 30 inch widescreen
computer monitors - they also made the Unity Motion displays too), Gateway Destination
(for their big screen computer systems), Panasonic, Philips, and a few other brands.
Some brands are actually pretty good, though right now I can really only recommend the
RCA and Princeton because of the consistent good reports I've heard. I haven't heard much
about the other brands, except negative ones like NetTV.
IMPORTANT: Avoid unfamiliar brands of big screen computer monitors. There are a lot of
headaches by many people who purchased NetTV big screen computer monitors, and lost
hundreds of dollars in shipping expenses before they were refunded (often a LONG time
later). Stick to the big names such as RCA instead - besides an RCA 36" computer
monitor looks sharper and brighter than a NetTV anyways, and are much more durable!
Warranty with brand name displays like RCA displays are a dream compared to NetTV
warranties. (Well, not really - but if you have heard of the NetTV horror stories, you'll
understand!)
Big Screen RP Computer Monitors
They are rear projection displays designed solely for computer graphics display. They
look like rear projection TV's you see in electronics showrooms, but are actually computer
monitors.
Most of these displays are digital. Because these are basically big boxes with a
specialized digital projector inside them, most things about digital projectors also apply
here too (screen door effect, fixed pixel resolution, lots of variance in picture quality,
etc).
A big advantage of the big screen rear projection computer monitors, include the
ability to leave the lights turned on. The picture also tends to be dazzling bright from
many of these displays, and in some cases much brighter than rear projection TV's.
These big screen rear projection displays are jaw-dropping when you see
blindingly-bright razor-sharp 1280x1024 computer graphics on a professional-brand
1280x1024 rear projection digital computer monitor. But when it comes to the litmus test,
motion video can sometimes look quite awful, posterized and cartoony on these displays
especially if they are optimized for conference room use.
Picture 4: Sony KL-W9000 50" rear projection monitor
The pictured Sony KL-W9000 is a widescreen model. It was found on the Net for an
amazing low price of only $2500 or less each, as it is a discontinued model. The
resolution is only 1068x480 but produces an amazingly good computer DVD picture. Be noted,
Sony has discontinued manufacturing these specific models and have went on to manufacture
different models, at much, much higher prices.
Recently, manufacturers have started making these displays for home theater use - such
as the Samsung Tantus 40 inch model. They are much more inexpensive but also tend to be
lower resolution (640x480).
Flat Panel Displays
One word: PRICE! As a result, you do not see many of these used for Home Theater
Computers. However, these flat panels can be a beautiful sight, especially if you choose a
high quality model.
Most of these are plasma technologies. They usually come in 40 or 50 inch diagonal
sizes. They are very thin - less than 3 inches thick and are very lightweight. They
usually can be mounted directly on the wall as well. Imagine a 50 inch display that weighs
only 75 pounds, for example! Try that with your living room projection TV.
Most of these are compatible as computer monitors, at various resolutions including
640x480, 856x480 and 1280x768. Some of these unusual resolutions will no doubt require a
video card such as Matrox G400 or GeForce256 able to output the exact resolution for best
results.
Picture 5: Pioneer Plasma Display
For most Joe Users, they are jaw-droppingly beautiful when you playback very bright
high-resolution source material on these displays.
Plasma displays tend to be fairly bad at displaying dark videos, because they sometimes
produce some christmas-lights-style digital background noise of red/green/blue dots.
However, I've only noticed this phenomenon on some of these displays so some brands must
be doing a better job.
HDTV Sets
HDTV sets are pretty much the new kid on the block when it comes to Home Theater
Computers. They are exciting and they are becoming more and more popular - these sets are
starting to be almost easy to find if you live in a big city. What more could you
want - walk into a store, and buy a HDTV to use as a computer monitor, without the
headaches and waiting time of mail-order for oversize products?
The recent advent of Mitsubishi, RCA, and Zenith HDTV sets with RGB capable inputs,
make them a viable contender* for Home Theater Computer use, with a whopping big
astericks involved.
* Asterik denotes you require a video card capable of outputting 960x540p and
1920x1080i in order to properly display graphics on a certain HDTV sets.
That's the main caveat. This basically means you require a Matrox G400 video card,
currently the only video card on the market known to generate the necessary 540p and 1080i
HDTV compatible output for RGB based HDTV sets. You also need one of the HDTV sets that
accepts RGB input. RGB is different from YPbPr. GeForce256 cards also work - though the
G400 has tended to be more HDTV-friendly because the G400 can do tricks such as doing
1280x1024i centered in the middle of 1920x1080i - perfect for videogames, and makes it
possible to play videogames at insane resolutions on a HDTV set. The GeForce256 cannot do
this, and the GeForce256 cannot support interlaced modes.
You cannot use a Toshiba HDTV set, because they currently only accept YPbPr component
video input (ColorStream Pro) and not RGB. Current computers cannot output YPbPr output
capable of working with HDTV sets, but this should change in the next few years as
manufacturers make HDTV-Out video cards (to supplement todays TV-Out video cards).
Be warned that HDTV sets are made for Average Joe User use, and are not designed as
computer monitors. They do not have elaborate picture adjustments. They do not normally
support standard computer resolutions. Showroom people will tell you that they won't work
with computers. But if it has an RGB input, ignore the showroom people and salesdroids -
trust the AVSCIENCE forum instead. You CAN display computer graphics in native high
resolution on an RGB-capable HDTV set!
Picture 6: Mitsubishi WS-73907 HDTV set
Some HDTV sets are actually not very sharp, so most of the time you will prefer
displaying 960x540 computer graphics instead of 1920x1080i. You'll also dislike the
interlaced flicker for high resolution computer graphics anyways - and like the 540p
better too.
Keep in mind, to the electronics of an HDTV set, 540p is exactly the same as 1080i (As
long as the sync frequencies and retrace intervals are the same). All 1080i CRT HDTV sets
can also do 540p even if the listed specs say that they are unable to do 480p. Did you
know that 540p is simply 1080i except with the two 540-line fields overlapping each other
instead of offset from each other? That's how Nintendo video game systems displays
non-interlaced graphics on your regular TV set - to create 240p out of 480i. Betcha you
didn't know that. It's a trick that analog CRT displays can do - you can halve the
vertical resolution to convert interlaced into non-interlaced, simply by overlapping the
two fields. The video timings remains exactly the same - same horizontal and vertical sync
frequency.
In fact, some HDTV sets only supports 1080i, but they can do 480p through the 540p
trick by adding 30 blank scan lines at the top and 30 blank scan lines at the bottom, to
create 540p at the same frequencies as 1080i. This allows sets to use just one 'memory' to
display all 1080i and 480p formats. The RCA DTC-100 settop box is one of the HDTV tuners
that can take advantage of this trick.
The benefit of 540p is that it's a high resolution perfectly capable of displaying
anamorphic DVD nicely, as long as it is slightly upscaled using a Home Theater Computer
(or slightly letterboxed with 30 blank scan lines at the top and bottom).
There are custom timings known by people in these AVSCIENCE forums you can use. You
also need a copy of PowerStrip software, which can be downloaded at www.entechtaiwan.com .
Remember, if you buy PowerStrip and if they ask you where you heard about them, tell them
that you learned about PowerStrip from the 'AVSCIENCE Home Theater Computer Forum'!
Lots of PowerStrip tweaking may be needed, because of various things like HDTV
overscan, as well as picture position and centering, because HDTV sets do not have
controls to position and size the picture properly. It can be quite difficult to do all of
this tweaking at first.
Show people DVD played back on a settop DVD player on a HDTV set. Now, show people DVD
played back through the DVDROM drive of a HT PC directly connected to the HDTV set - and
watch their jaws drop! The picture quality improvement is that significant,
especially if the HDTV set does not contain a line doubler for external video
sources."
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