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 exagerated 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 transition figures

  • The higher the brightness, the better

  • The higher the contrast ratio, the better. This will also help indicate the black depth of the screen

  • The wider the viewing angles the better

I would really recommend reading further into the details about monitor specs before you make your purchase so you can understand what they infer about the monitors performance characteristics. More importantly you need to understand the differences between the varying panel technologies used in the market as this will give you a much better feel for the expected performance characteristics.

 


Q. What Specs Should I Be Cautious Of?

A. There are quite a few specs which are either massively exagerated or need caution. Here are some which you need to be aware of:

  • Dynamic contrast ratios - perhaps the most overly exagerated 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 descreased. 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 realiable spec. In practice you would never acheive 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 at all!
     

  • Response time - Generally the lower the response time the better, but you need to understand the impact panel technolgy has on practical responsiveness. Also understand the difference between panels with and without 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 considerations. See this article for more information.

 


 Q. What Is the Best Panel Technology To Get?

A. An important thing to consider is what 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 panel technology used. The most common technologies used are TN Film, IPS, MVA and PVA. 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 than another. They still all 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. For more information about panel technologies, see this article

 


 Q. Should I Worry About 6-bit vs 8-bit Panels?

A. There is a lot of talk about colour depth on TFT screens. 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. Yes, 8-bit displays are preferable, and can offer an improved colour palette, more freedom from grading and banding, and are the choice for colour critical displays. However, modern 6-bit screens use a range of FRC technologies which can offer some decent results. On some 6-bit +FRC panels colour range is good, screens show no obvious gradation of colours, and they show no FRC artefacts or glitches.

Manufacturers use 6-bit panels (+FRC) to help keep costs lower, and for the majority of users I would suggest it is difficult to tell the difference in practice between a 6-bit or 8-bit panel. Colour accuracy of modern 6-bit panels (mostly TN Film) is also very impressive, an area which used to be lacking. If you're an average user, you shouldn't worry too much about the situation too much, most users will find a 6-bit panel perfectly adequate for their needs. If you need a display for colour critical work, then you should certainly consider the graphics range from manufacturers which all use 8-bit (or above) colour depth. See here for more information.

 


 Q. Should I Be Worried About Ghosting?

A. Generally nowadays with all the 5ms, 4ms and 2ms models available, ghosting is just not an issue for the majority of users. Choosing a TFT can commonly 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 signifcant improvement in responsiveness in practice and quoted response time specs began to fall even more. If you are wanting to game a lot of feel you are particularly sensitve to blurring and ghosting then you should look for a screen with a quoted "G2G" (grey to grey) response time. These models use RTC technology which reduces blurring considerably in practice. Have a read here about response times if you are unsure about what specs mean.

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 Black Frame Insertion, Motion Picture Acceleration, and 100Hz / 120Hz LCD technologies. See here for further information about those technologies.

Ghosting may also depend on how susceptible you are to things like this, 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!

 


 Q. Does DVI Make A Difference?

A. This can depend a lot of the monitor in question. DVI offers a pure digital end to end connection between the graphics card and the monitor. VGA on the other hand 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 utlised 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.

Typically screens which don't have DVI connections offer very good quality VGA connections. Perhaps manufacturers spent more time and effort perfecting these, knowing it was all they could offer the user. On the other hand, maybe manufacturers who offer both connections don't spend as much time or money making the VGA as good as it could be, since they assume users will always use DVI anyway. This seems logical, and in practice there is a host of screens which show this trend.

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 PQ using this interface.

 


Q. Should I Use HDMI or DVI?

A. If your screen has both an HDMI and DVI interface you can use either for an end-to-end digital connection. HDMI will allow you to carry audio as well, but from a video point of view it is the same as DVI. In theory there should be no benefit in using one of the other when it comes to image quality. However, some HDMI interfaces are subject to further image processing and technologies when the signal reaches the screen. These are usually designed with external games consoles/DVD players/Blu-ray players in mind where added multimedia enhancements are of benefit. These are the same kind of technologies as featured in LCD TV's. If the monitor is equipped with these technologies then using the HDMI interface to connect your PC might result in a different image to when using DVI (which bypasses all these technologies). It can sometimes lead to artefacts and rounding of text for instance which might not be ideal.

If your screen features both DVI and HDMI you can try both to see which is preferred. If it only features HDMI then one would hope that these extra 'enhancements' are not featured or at least can be turned off. Many screens are packaged with DVI > HDMI convertor cables in case you do not have the matching interface available on your graphics card or if only one option is available on the display.

 


 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/dusting 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 cloths for lens cleaning are also very good.

For the perfectionist, there is "Lindy" brand TFT cleaner. It costs about £4 for a pump-dispenser. You can pick it up at office supply stores and computer fairs.
 


 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 described in the following ways:

  • Fully dead - stuck on black of white

  • Dead Sub Pixel - Stuck on Red / Green / Blue

  • 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.

They 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 5 full screen colours (black/white/red/green/blue) to check for dead or lazy pixels (use UP key) 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! (SPACE key). ESC key ot exit.

If you want to insure 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 insure 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 Governement Regulations (page 11 in particular). This selling act is not qidely known 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 regularly updated TFT Selector which will hopefully help you decide on the screen which suits your needs. You also need to base your decision on the looks of the TFT, any extra functions which you might find useful, and the price.
 


 Q. Where Can I See User's Pictures Of Their TFT's?

A. Try this thread on Overclockers... there's loads of good pics of people’s setups