Frequently Asked Questions
Q. What Should I Look
For In The Quoted Specification?
A. The first thing to realise when buying a
new screen is that you can't always rely on quoted specifications. These are
often exaggerated for marketing purposes, and are commonly based on different
measurement techniques and varying benchmarks between each manufacturer. As a
guide and general rule of thumb:
The lower the
response time the better. Be aware of ISO response time figures and grey
to grey (G2G) transition figures as you will need to understand the
difference. Screens with a G2G quoted response time use ‘Response Time
Compensation’ (RTC) technologies, sometimes referred to as overdrive. These
technologies are used to boost pixel response times and in practice can make
quite a lot of difference. This is particularly important with non-TN Film
panels (i.e. IPS, PVA, MVA etc)
The higher the
contrast ratio, the better. This will also help indicate the black depth
of the screen and how well the screen can handle differences between light and
dark content. Be wary of
dynamic contrast ratio figures being quoted nowadays and you will need to
understand what the difference is between those and the ‘static contrast
ratio’. Nowadays you will see static contrast ratio figures ranging up to
~5000:1 in some cases. DCR can range up in the millions:1 but are massively
exaggerated. Make sure you understand which contrast ratio figure is being
quoted in a spec and ideally read a review where it is really tested.
The wider the
viewing angles the better. Be wary of how they calculate their figures.
Sometimes they will try sneaking things like listed them when CR > 5 instead
of when CR > 10 to inflate their numbers. Again real life performance might
not match quoted specs. You will normally see TN Film panels listed with a
170/160 viewing angle (a classic indication that the screen is using TN Film
technology by the way). IPS, PVA, MVA and PLS panels will normally feature a
178/178 viewing angle spec, but in reality the performance does vary.
Perhaps the most important
'spec' to consider if the
panel technology being used in the monitor. This is not always provided
but if in doubt you can use our
panel search tool to identify a particular model's panel technology.
I would really recommend reading further into the details about
before you make your purchase so you can understand what they infer about the
monitors performance characteristics.
Q. What Is the Best Panel Technology To Get?
A. A very important thing to consider is
panel technology the screen uses you are interested in buying. While specs
may look similar on paper, performance may vary quite considerably between the
models due to the underlying panel technology used. The most common technologies
used in the desktop monitor market are TN Film, IPS, MVA and PVA (and various
variations thereof). More recently in 2011 Samsung
also introduced a new technology called PLS which, while in its infancy, is
designed to compete with the popular IPS technology. These are all produced by a
range of panel manufacturers and offer a variety of strengths and weaknesses.
There is a reasonable amount of talk about panel technologies with many people
quick to jump on a bandwagon and claim one is superior to another. To be honest,
they all still have their place in the modern market, and due to their different
characteristics, can play a key part in finding the right monitor for your use.
There are various generations of each technology as well, and different
manufacturers have slightly different names for their versions. Look out for
TN Film (Twisted Nematic +
Film) = pretty uniform in naming, developed by many manufacturers
including all the larger suppliers
IPS (In Plane Switching)
= S-IPS, H-IPS, e-IPS, AS-IPS, AH-IPS, p-IPS, generally all developed by
MVA (Multi-domain Vertical
Alignment) = S-MVA, P-MVA, AMVA, generally developed by AU Optronics and
some from Chi Mei Innolux (formerly CMO)
PVA (Patterned Vertical
Alignment) = S-PVA, cPVA, a Samsung technology exclusively manufactured by
PLS (Plane to Line
Switching) = S-PLS, a Samsung technology exclusive to them
For more information about panel technologies, see
this detailed article which is often updated.
Q. What Specs Should
I Be Cautious Of?
A. There are quite a few specs which are
either massively exaggerated or need caution. Here are some which you need to be
Dynamic contrast ratios - perhaps the most
overly exaggerated specs in the modern market. You will see figures in the
millions now, but these are largely meaningless.
Dynamic contrast ratios involves controlling the backlight of the screen
automatically, depending on the content shown on the screen. In bright images,
the backlight is increased, and in darker images, it is decreased. There is no
real need to have a DCR of over 10,000:1 as you just wouldn't notice the
difference in practice. The figures being quoted now are based on measurements
of monitor states which would just never occur in real use. In fact modern DCR's
of LED backlit screens assume the "black" state is in fact when the backlighting
is turned off, in which case DCR would effectively be tending towards
infinity:1. Just ignore DCR figures are they are not a reliable spec. In
practice you would never achieve the numbers quoted. Far more important really
is how effective the mechanism is and whether it is smooth and at what speed
changes are made. Also keep in mind many people don't even like the technology
Response time - Generally the lower the
response time the better, but you need to understand the impact
panel technology has on
practical responsiveness. Also understand the difference between panels with and
Response Time Compensation (RTC) / Overdrive technologies as that can have a
significant impact. Don't rely purely on a quoted response time figure on paper.
Colour gamut - don't assume that a higher
colour gamut is better! The gamut represents the colour space that the
backlighting unit of the monitor allows the screen to display. You need to
understand that most normal content is based on a certain colour space (sRGB)
and that there can be issues if you view this using a wide gamut screen.
See here for more information.
Backlighting - LED backlighting is becoming
increasingly common in modern screens with manufacturers making a lot of claims
which aren't necessarily true. You need to understand what different
backlighting will actually offer you. In reality, LED backlighting in mainstream
screens is based on White-LED (W-LED) backlight units and only really offers
benefits in terms of power consumption, screen thickness, and in environmental
this article for more information.
Q. Should I Be Worried About Ghosting?
A. Generally nowadays with all the 5ms, 4ms and 2ms
response time rated models available, ghosting is just not an issue for the
majority of users. Choosing a TFT can therefore often be based on design and
looks, price and any extra features you might need. The fast response times of
the panels used now are perfectly adequate to cut out pretty much all obvious
ghosting and blurring, even in fast paced games. There are still some users who
find the move from CRT screens to TFT a difficult change, but more and more
users are switching over. With improving technologies being used, motion blur is
becoming less of an issue.
Some time ago it is considered that a response time of 25ms or less should be
fine for gaming in most cases. Panels with 16ms, 12ms and 8ms became common
place and ghosting has become even less of a problem. The advent of overdrive (RTC
technologies) saw a significant improvement in responsiveness in practice
and quoted response time specs began to fall even more. This technology really
helped improve response times with VA and IPS panels, finally making them
feasible for gaming in many cases. Look out for response time specs quoted with
a “G2G” (grey to grey) response time as that should indicate the use of
The arrival of other technologies designed to reduce perceived motion blur looks
set to offer another marked improvement in the performance of LCD displays.
These include the rarely used Black Frame Insertion (BFI) and Motion Picture
Acceleration (MPA) technologies. However, more important in recent times has
been the development of
120Hz LCD technologies. Nowadays screens supporting 120Hz input frequencies
are becoming more and come common, and these can help reduce motion blur and
ghosting and improve gaming performance considerably. They are also able to
support higher frame rates than traditional 60Hz displays and are also capable
of supporting 3D stereoscopic content through active shutter glasses. Do be
careful of assuming that a screen advertised as supporting 3D is in fact able to
support 120Hz though, as some 3D models do not support this and instead use
passive methods to produce the 3D effect (see
here for more info on 3D technologies)
Ghosting and motion blur perception may also depend on how susceptible you are
as a user, as one person may see no ghosting, another may see lots on the same
panel. The best bet is to try and see a TFT in action in a shop and see for
yourself, if that’s not possible you will have to settle for the opinions of
other users and take the plunge! Also be careful to get an idea of real life
performance in practice, and don’t just rely on quoted specs. While they are
often a good rough guide to the gaming performance, they are not always
Have a read
here about response times if you are unsure about what specs mean or want
more information. Generally modern TN Film panels will offer the fastest
response times, and often also support 120Hz input frequencies for 3D support /
extended frame rates. Look out for models with a quoted “G2G” response time
indicating they also use overdrive which can really help in practice. Modern IPS
panels can also be very fast where overdrive is applied well, so again look for
“G2G” figures. Other technologies like PVA and MVA are unfortunately quite slow
in practice by modern standards, even where overdrive is used. Check reviews to
be sure of an individual screens performance wherever possible.
Which Video Interface Connection Should I Use?
A. As a rule of thumb, it would normally be best to use the digital
video connection end to end to connect your device to your monitor. For a
PC, this would generally be DVI which offers a pure digital end to end
connection between the graphics card and the monitor. D-sub/VGA on the other
hand is often available as well, but has to convert the signal to analogue. In
theory, digital connections should therefore offer a superior picture quality
and a sharper image. In practice, this can depend on the model in question.
There are a number of sharpening algorithms utilised for modern VGA interfaces
which vary in the quality of the analogue/digital conversion. Some modern
screens have such good analogue connections that it is very hard, or even
impossible, to tell the difference between VGA and DVI. If you can use DVI, then
you should, since it will offer the sharpest image available for the screen. If
you are limited to VGA only, I'd suggest finding some user opinions or reviews
about the picture quality (PQ) using this interface.
HDMI and DisplayPort are also common digital connections now being offer, but
unlike DVI are also capable of carrying audio as well as video. The PQ should
not be any different between DVI and HDMI/DisplayPort in theory as long as no
additional video “enhancements” are applied when using one over the other.
Another thing to keep in mind is the maximum resolution supported from different
connections and the native resolution of the screen you are using. For instance,
a screen with a 2560 x 1440 or 2560 x 1600 resolution would require a Dual-link
DVI (dual link is still a single connection, just with a higher bandwidth
supported) or DisplayPort to operate at full resolution. HDMI and D-sub do not
have the required bandwidth to support that full resolution.
Q. Should I Worry
About 6-bit vs. 8-bit vs. 10-bit Panels?
A. There is a lot of talk about
colour depth on TFT screens, now more than ever with the emergence of 6-bit
IPS and VA panels. At one time TN Film was the main 6-bit technology but today
that is no longer the case. It's important to put this into perspective though,
and not jump on the bandwagon of 8-bit being much, much better than 6-bit. Or
even 10-bit being much better than 8-bit.
An 8-bit display would offer a colour palette of 16.7 million colours. They
offer a 'true' colour palette, and are generally the choice of manufacturers for
colour critical displays over 6-bit panels. On the other hand modern 6-bit
screens use a range of
Frame Rate Control (FRC) technologies to extend the colour palette from
262,144 colours to around 16.7m. In fact on many modern panels these FRC are
very good and in practice you’d be hard pressed to spot any real difference
between a 6-bit + FRC display and a true 8-bit display. Colour range is good,
screens show no obvious gradation of colours, and they show no FRC artefacts or
glitches in normal everyday use. Most average users would never notice the
difference and so it is more important to think about the
panel technology and
your individual uses than get bogged down worrying about 6-bit vs. 8-bit
Manufacturers use 6-bit panels (+FRC) to help keep costs lower. As a result, a
modern range of IPS and VA panels is also now produced which use 6-bit colour
depth (+FRC) instead of true 8-bit colour depths. At the other end of the scale
there are also some panels which can offer support of 10-bit colour depth. Again
these come in two flavours, being either a true 10-bit panel (very rare and
expensive) offering 1.07 billion colours or an 8-bit panel with an additional
FRC stage added (1.07 billion colours produced through FRC). The 8-bit +FRC
panels are of course more common and will often be used to offer “10-bit”
support in desktop displays. With 10-bit colour though there is also an
additional consideration which is whether you would ever even be able to use
this in your work. You can also only make use of this 10-bit support if you have
a full end-to-end 10-bit workflow, including a supporting software, graphics
card and operating system which is still very rare and expensive for most users.
Note: Colour depth in this regard should not be confused with
Q. What Does a Monitors Colour Gamut
Colour gamut or colour space refers to the range of colours which the screen
is capable of showing, in relation to a reference colour space. The human eye
can see a certain range of colours which is represented by a
CIE Diagram. This shows the full range in reds, greens and blues which the
eye can see. Within that massive range there are various reference colour
spaces, the most common of these being the sRGB space. There are also other
reference colour spaces such as the NTSC and Adobe RGB which are often used in
specifications nowadays and may be used in certain workflows. These are larger
colour spaces than sRGB, so manufacturers needed a way to quantify the changes
they had made.
The colour space / gamut capability of a monitor is not determined by the panel
technology, but rather by the backlight technology being used. Traditional
screens used standard CCFL backlighting which (for simplicity of comparison
here) offered a colour space covering the sRGB space almost exactly, which
equates to about 72% of the now popular NTSC reference space. With backlighting
technology changes and improvements, some screens then started to use WCG-CCFL
(Wide Colour Gamut CCFL) backlighting which can offer an extended gamut covering
commonly 92% - 102% of the NTSC reference space. Other backlighting technologies
like W-LED (White LED) are also becoming very common, and at the moment cover
the sRGB space (~68 – 72% NTSC). Some other LED backlights using RGB LED can
cover >100% of the NTSC space as well but are prohibitively expensive and rarely
While a larger colour space might sound like a good idea, it's not always for
everyone. You need to keep in mind what content you will be viewing on the
screen, and what colour space that content is based on. Since sRGB is very
common and the standard for many things like Windows and the internet, viewing
sRGB content on an extended gamut screen can cause oversaturation of colours and
an unrealistic 'stretching' of the colours. Reds and greens in particular can
appear quite 'neon' and some users do not like this. The smaller colour space of
the content is, as a very crude description, 'stretched' over the larger colour
space of the monitor. On the other hand, some applications are colour space
aware (e.g. Adobe Photoshop) and so if you are working with extended gamut
content, you will prefer an extended gamut screen. I'd certainly recommend
reading more into this as it is only a brief summary here. Where a screen has an
extended gamut, they sometimes provide an sRGB emulation mode which work to
varying degrees. Handy if you might need to use it, but make sure the screen
offers a decent performance when in this mode and that it works. At the end of
the day, the choice of monitor might very well depend on the colour space you
want to work with. For most average users a standard CCFL or W-LED backlit
display with a standard sRGB gamut would probably be preferred.
Q. What's The Best Way
To Clean a TFT Screen?
A. The simplest and cheapest way to clean a TFT screen is with a slightly
damp cloth; wipe off the left behind water with a towel or similar then
smooth/dry completely with a yellow polishing cloth. Be careful not to use
products such as toilet paper and kitchen roll as they contain lint and can
leave scratches on your beloved screen! Cleaning solution from opticians and
lint free clothes for lens cleaning are also very good.
For the perfectionist, there are also some very nice microfiber solutions
available such as the
‘Cloth Addiction’ range.
Q. What's The
Situation With Dead Pixels?
A. Unfortunately dead pixels can be an issue on TFT screens as they are
often developed during the manufacturing stage. For retail costs to be kept low
the companies cannot afford to make all screens defect-free and check for dead
pixels all the time. Pixels can be described in the following ways:
Fully dead - stuck on black
Dead Sub Pixel - Stuck on Red
/ Green / Blue permanently
Lazy - stuck on a colour, but
sometimes can change. If the pixels are only lazy, there may be hope of
reviving them. If they are fully dead, they will stay that way.
Dead pixels very rarely develop during use, unless you have a habit of poking
the screen. If you are careful with the screen, hopefully you shouldn't develop
any further pixel problems.
To test for dead pixels, there is "Dead Pixel Buddy"
program available. You can manually cycle through different full screen
colours (black/white/red/green/blue) to check for dead or lazy pixels or rapidly
cycle through all of the colours automatically to try and coax lazy sub-pixels
back to life. Leave it running for half an hour, if you're lucky it can work!
If you want to ensure that you receive a pixel perfect screen (and who wouldn't
at the kind of prices you are paying for the TFT!?!) then you can often pay for
pixel checks from some online retailers. Beware though! Never buy a TFT from
retailers who offer the pixel check without having the check done as you can be
sure the screens they find to be non-perfect will be winging their way to the
customers who don't have the check! The only other option to ensure you get a
pixel perfect screen is to check out the panel in a shop in person, then you can
see for yourself.....
If you find you have a dead pixel there is not a lot you can do unfortunately.
If you have a certain number of dead pixels (usually at least 3 or a certain
number centrally on the panel) then the manufacturer will replace the TFT for
you, but the number of dead pixels needed before this happens varies between
each manufacturer, so check with them before you order if you're concerned.
Some lazy pixels can be bought back to life occasionally. Playing some fast
paced games for a while, and massaging / flicking the pixel area with a lint
free cloth can sometimes help revive the lazy pixel, but not in all cases.
If you still have a dead pixel problem, can't bring it back to life and can't
RMA it under warranty then you can sometimes return it to the stockist if you
purchased it online. If you bought online you can take advantage of the
"Distance Selling Act" which entitles you to return any item within 7 days as
you were not present at the time of purchase. If you are not happy with your TFT
you can return it at your cost of postage and often claim a refund or exchange.
However, be aware that a lot of places will try and charge you restocking fees
and they will almost certainly specify the goods must be packaged and in the
same condition as when you received it, so be careful to package it back up
nicely. Legally, if the stocker accepts the TFT back as a return governed by the
Distance Selling Act, then they are NOT allowed to charge you a restocking fee
as covered in the
Government Regulations. This selling act is not widely advertised by
retailers, but does exist if you really need to use it. You should only have to
pay for postage to send it back to them.
Q. So Which
Is The Best TFT To Get?
A. This question pops up ALL the time! It really depends on what you want
the TFT for, how much you want to pay etc. Performance varies with different
panel technologies and with different specs. Check out the
TFT Selector Tool which will hopefully help you decide on the screen which
suits your needs and is regularly updated. You also need to base your decision
on the looks of the TFT, any extra functions which you might find useful, and