ali wrote:
> Selamat pagi rekan semuannya,
> sekarang ini monitor PC banyak pilihan & murah meriah khususnaya type LCD.
> saya berencana utk memakai monitor LCD tetapi dari banyaknya pilihan yg ada
> saya belum tahu mana yg baik/bagus, mohon masukan dari rekan's, untuk memilih
> LCD monitor yg bagus, spesifikasinya harus yg bagaimana?
> terima kasih sebelumnya.
> tk.
> Kilwalaga
>
> [Non-text portions of this message have been removed]
>
>
>
>
Maaf beribu maaf, agak panjang.. saya anggap tidak semua bisa buka web,
karena juga cuma teks.
saya ambil dari http://www.oprekpc.com/forum/viewtopic.php?p=80031
1. Criteria
----------------------------------------------
* Color gamut
"Color gamut" represents the range of colors that can be displayed using
combinations of red, green, and blue subpixels. Certain monitors must
emulate the colors (by dithering or frame rate control (FRC)) to display
the full 24-bit of today's graphics adapters.
* Black level (darkness of the color black)
LCDs require a source of light to display an image. Most today use cold
cathode fluorescent lights (CCFLs), while more expensive ones use LED.
With either technology, the crystals have a hard time blocking the
light. How well they can do this is quantized by the black level. This
measures how many nits (candelas per square meter) are emitted when
black is displayed. Lower the better for black. For white, you'd want
the highest value possible. The low black and the high white brightness
values will produce a high-contrast display, and that's what you're
looking for in terms of colors.
* Response time
Response time measures how long it takes for one crystal cell to change
its state from on to off. Some types of panels are faster than others in
this category. The lower value of time (usually milliseconds) means a
quicker change. A high response time can cause blurry/streaky effects in
motion. A technology called ODC (overdriving circuit) can assist in
reducing these effects.
* Viewing angle
The viewing angle measurement denotes how far to each side it is that
you can still make out an undistorted image. This varies among panels as
well, as do all of the above. On TN panels, the colors will invert when
viewed at an extreme angle. VAs will generally just decrease in
brightness with little color shift. IPS panels exhibit the fewest
effects when viewing from a different angle.
* Input flexibility
Many monitors come with both a DVI (Digital Visual Interface) and VGA
(Video Graphics Array) interface. DVI will deliver a perfect pictures in
terms of geometry due to its digital nature. VGA, analog, can sometimes
be noisy or blurry. Generally the difference is insignificant on LCDs
17" or smaller.
* Ergonomics
LCDs can be very flexible with physical adjustments. These may include
height adjustment, tilt, swivel, pivot, and rotate (portrait/landscape).
It shouldn't come as a surprise all measurements are biased when it
comes to manufacturers' specifications.
----------------------------------------------
2. Types of Panels
----------------------------------------------
The most important thing to consider is the type of panel in the LCD.
(Please note that no guarantees are made regarding the accuracy of the
scientific details on these panels.)
* TN (Twisted Nematic): Without an ODC (overdriving circuit), this type
of panel offers the fastest pixel response time. This does however come
at the expensive of viewing angles and color fidelity. Out of all
TFT-LCD panels, the TN type has the lowest contrast. It is also a 6-bit
color depth panel, meaning dithering or frame rate control (FRC) must be
employed to reach close to a full 8-bit depth. Pixels in their active
state on a TN are black, while in their inactive, white.
* (P-)MVA ({Premium} Multidomain Vertical Alignment): The liquid crystal
(LC) cells on MVA panels are in their active state white, and in
inactive black and are separated into four domains. This slightly
improves viewing angle over TN-type displays (MVAs provide ~45 degrees).
MVA panels also provide a high contrast ratio. Grayscale inversion is
minimal on these displays. Response time is the second slowest in the
industry without ODCs. MVAs and all derivatives hide details at a
perpendicular viewing angle due to their multidomain nature.
* PVA (Patterned-ITO Vertical Alignment): Developed by Samsung, PVA is
very similar to MVA. Viewing angles are very similar and inversion is
minimal at wide viewing angles. Samsung is not clear on the true color
depth of these panels. These panels deliver the slowest response time.
* S-PVA (Super Patterned-ITO Vertical Alignment): These types of panels
deliver a full 8-bit color depth and have a structure split into eight
domains. At wide viewing angles, they have less color shift and a lower
black level than MVAs. According to Samsung, they have a higher contrast
ratio and better response time than MVAs as well.
* S-MVA (Super Multidomain Vertical Alignment): Likely similar to P-MVA
from AU Optronics, Chi Mei Optoelectronics has developed the S-MVA type
of panel. These also include multidomain, vertically-aligned liquid
crystals so that the cells stay in the same shape at different
positions, increasing brightness at wide viewing angles. According to
CMO, S-MVA improves viewing angles from conventional MVA types to 80
degrees in all angles. Like other types of panels, response time has
gradually improved on these as well.
* IPS (In-Plane Switching): The IPS panel was pioneered by Hitachi to
fix the problems that plague the VA and TN types. Like TN, most IPSes
contain only a single domain, although DD-IPS (dual domain IPS) does
exist. This technology sports the least distortion at wide viewing
angles. Two transistors per each pixel are needed, so brighter
backlighting is crucial and power consumption is higher than competing
technologies, but response time benefits greatly from this. Color depth
varies. One disadvantage is that a purple-black is now introduced in
black colors at different viewing angles.
* S-IPS (Super In-Plane Switching): LG Philips LCD improved on IPS with
their S-IPS technology. These offer a lower black level, higher contrast
ratio, lower response time, and a wider viewing angle than traditional
IPS technology. Color depth on S-IPS panels is 8-bit. The purple-black
tinting still applies to wide viewing angles, but orange and red hues
are greatly reduced versus other technologies at wider viewing angles.
* AS-IPS (Advanced/Enhanced Super In-Plane Switching): These type of
panels are LG Philips LCD's third generation of IPS technology. This is
mainly just a wieldy moniker for improvements in the front-end driving
electronics, including ODC to reduce response time, and a dynamic
contrast ratio technology, raising contrast up to 1600:1. The diagonal
viewing angle is also increased to 178 degrees, from 170 on S-IPS
panels. AS-IPS panels very often include much brighter backlights than
S-IPS types.
* A-MVA (Advanced Multidomain Vertical Alignment): This is a new panel
from AU Optronics promising contrast ratio and viewing angle performance
comparable to Samsung's 8-domain S-PVA panels. These should be capable
of true 8-bit color. Still, it is unknown if ODC will force them to dither.
----------------------------------------------
3. Aspect Ratios and Resolutions
----------------------------------------------
Aspect ratio is a proportion representing width divided by height.
Common aspect ratios are listed below.
* 5:4 (1280x1024 for 17" and 19"): Squarest of all the listed, thus
maximum area.
* 4:3 (1600x1200 for 20.1")
* 16:10 (1680x1050 for 20.1", 1920x1200 for 24"): Resolution of most
"widescreen" monitors
* 16:9 (1280x720, 1920x1080): True widescreen. No LCD monitors that I
know of incorporate this HDTV resolution with one exception, this
Westinghouse 37", but this is more of a TV due to its size. 16:10 is the
commonly used one for monitors because it's a good compromise between
productivity (Word documents anyone?) and movie watching.
As for scaling quality, it first depends on if you tell your graphics
card to do it, or your monitor. If you find your monitor's scaling is
sub par, you can engage your graphics card's scaler. In addition there
are a number of scaling modes, like 1:1 and fixed aspect ratio scaling.
Many monitors deliver OK scaling when viewing photos, however text
clarity can easily suffer. Games may not look very pleasing at lower
resolutions.
----------------------------------------------
4. Technologies
----------------------------------------------
* Overdrive (Response Time Accelerator)
Most commonly called ClearMotiv (ViewSonic), MagicSpeed (Samsung), Over
Driving Circuit (LG.Philips LCD), and Response Time Compensation (X-Bit
Labs). All of the above technologies bump the voltage to increase the
speed of the transition (among other things in the case of ClearMotiv).
When it goes too far (an overshoot), there can be noise, especially
noticeable in subtle transitions or the dithering of TN panels. Tom's
Hardware Guide does however have a rating for this overshoot phenomenon.
X-Bit Labs has also cracked down on it in their recent reviews.
* "Widescreen" (16:10 AR)
Usually widescreen means 16:9, but LCD monitor manufacturers use the
moniker widescreen to refer to a 16:10 ratio instead, a compromise
between desktop real estate and movie watching. While it may sound great
at first, there are a lot of things to consider. Is widescreen all it's
cracked up to be?
The main problem with widescreen is the resolution itself. As you may
know, LCDs can not change their resolution without a loss of quality,
and most of the time it's a significant loss of clarity. CRTs can do
this much better because they inherently have a Gaussian distribution of
the pixels, and in the end it yields much better quality. Think of it
like analog zoom vs. digital zoom.
This means in order to get a good image on a widescreen monitor, you
must run it at its native resolution, or deal with black bars on the
edges. I'd say 75% of today's games still require you to edit a
configuration file manually to achieve the widescreen resolution.
Fortunately, many people have already done the grunt work for you.
Here's a site that will help you configure your game to work with your
widescreen LCD: Widescreen Gaming Forum
But, not all games can support widescreen, even through the
configuration file. For these, you'll have to settle with the black bars
or scaling.
* X-Brite/OptiClear/Acer CrystalBrite
These are special contrast-increasing coatings. Note, Samsung's
MagicBright/MagicColor and BenQ's SensEye are not necessarily related to
these, they are internal panel technologies. Anyhow, many people prefer
the higher contrast of these coatings and say they look beautiful. One
small note of concern is they could increase glare, but that'll depend
on the ambient lighting surrounding you.
* HDCP
High-Bandwidth Digital Content Protection. Supposedly, this will be
mandatory for playing High-Def Windows Media DRM on Windows Vista, and
possibly Blu-Ray/HD-DVD players. You won't need it to boot into Windows
though (not even Vista). HDCP can be used through the DVI port or
through the HDMI port. It's hardly anything to worry about for computer
monitors (very few have it), but you should definitely consider it for
multimedia monitors and TVs.
----------------------------------------------
5. "Ghosting"
----------------------------------------------
Maybe you've looked at LCDs before, and find the colors great, the
viewing angles good, but one thing you are especially worried about with
your future purchase is the response time. There's a fundamental problem
in explaining how good or bad the level of ghosting is. This may be the
only way I can relate it to you: if you've ever used an aperture grille
CRT and seen its faint lines but still love it regardless, the same
thing will probably happen to you with response time.
Obviously the first week you get it, that's the first thing you're going
to look for, because for most gamers it's the obvious disadvantage. So
you bring your LCD home, plug it in and play some Battlefield 2 on it,
then turn around a bit, and you can see some smearing. At that point,
you're probably already thinking of returning it and thinking you'll
never be able to live with it. In reality, once you take your focus off
scrutinizing the ghosting and start playing your game, you will find it
to be an extremely small obstruction, if it is any problem at all. In
the end, that's all that matters. It's also worth noting some people may
not even be able to see it if they look for it. Unless you have a panel
with an atrocious response time like 25 ms. (min), then it will be a
minor issue. That said there are some people who may be especially
sensitive to it.
----------------------------------------------
6. Backlight Uniformity/Leaking
----------------------------------------------
Unfortunately, this can vary a lot per unit. If uniformity is bad, some
places on the panel will be slightly brighter than others. This still
occurs today, especially in cheaper monitors. However even more
expensive ones have their share of duds, such as the VP191b/VP930b,
which many users have had leaking issues with, along with some of the
Dells. But like I said, this will vary per unit. The majority of the
time, this is not a problem.
----------------------------------------------
7. Common Misconceptions
----------------------------------------------
* An IPS or VA panel is always 8-bit
Just because the crystals themselves have the ability to twist that
accurate does not necessarily mean the driving electronics can support
it. Don't rely on this. For instance, the Samsung 970P and ViewSonic
VP930b use a form of dithering/FRC.
* 16.7 million colors is a connotation for a dither-free 8-bit panel
You cannot count on this measurement to be true among manufacturers.
* A lower-listed response time on the specifications is always faster
This is very untrue. Manufacturers can measure the response time any way
they so desire. Gray to gray, white to black and back to white, only the
rise time, only the fall time, or any combination of those. One
manufacturer's "20 ms." can be another's "4 ms." Beware. For example,
the Samsung 940B is rated as 8 ms., but it reaches 35 ms. most of the time.
* Contrast ratios
Usually the contrast ratios are grossly overrated on spec sheets and
there's no telling if they're using the standard ANSI method.
* Viewing angles
This is yet another inflated spec. 160/160 can mean 80/80 up/down and
80/80 left/right or 40/120 up/down and 90/70 left/right. You can't tell.
Some manufacturers will list their method as CR>5 or CR>10, this means
it maintains a contrast ratio>x at y angle. But there will still be
immense distortion on some panels, particularly TN. It does not take
that in to account.
* Bigger is better
When you compare a 17" to a 19" which both have a 5:4 1280x1024
resolution, the 19" only has bigger dot pitch. This means your display
will be grainier in general, though text will be bigger for the
visually-impaired. Unfortunately, manufacturers are mostly only spending
R&D on 19" panels nowadays, and some are even cheaper than their 17"
counterparts.
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