You have probably heard it before, but it bears repeating...the best way to know if a monitor is right for you is to view it in person. Specs are a great tool for narrowing down your choices, but they are no replacement for hands-on experience. Plenty of large resellers stock a wide range of monitors and some are on display. Go down to every shop you can and see if you can find the monitor you are thinking of buying. You never know, that slightly low spec one you shunned in favour of that extra inch of screen may beat everything else hands down in real world performance.

The Minor Issues

Dot Pitch/Pixel Size

Dot pitch is the distance between phosphor dots (sub-pixels) or between TFT LCD cells of the same color on a display screen. A smaller number generally means that the image on the screen is sharper, as there are more dots in any given area.

A display with a smaller dot pitch is usually better, but this is not always true because of the methods used to measure it. There are many methods of measurement as well as differing pixel geometries on the screen and differing screen resolutions when judging image quality on the display.

Most of the time, dot pitch is measured on the diagonal, this gives the most accurate representation of dot pitch of the display. Later some companies introduced a horizontal dot pitch measurement. By measuring only the horizontal dot pitch and not the vertical, cheap, low-quality displays can appear to have a smaller dot pitch.

For example, a display with a 0.28mm (diagonal) dot pitch has a horizontal pitch of 0.24 or 0.25mm depending on some monitor construction variables, a good quality 0.26mm (diagonal) display has a horizontal pitch of 0.22mm.

Be careful not to get the two different measurements confused as that 0.26mm dot pitch monitor may have more dots per millimeter than the 0.24mm dot pitch display.

Contrast and Brightness

Contrast is the ability for the monitor to vary brightness between the foreground and the backgound. It is expressed in a ratio ( i.e. 500:1). Typically the higher the ratio, the better the image quality will be as the display will be able to show bright colors next to dark without washing out the black or dulling the colors. Display brightness is expressed in candela (cd) and is defined formally as:

Phew, what this means to us it that the greater this number, the brighter the display is capable of being. However, you must watch the power consumption of the unit. A display that has a very high brightness level will consume more power than others with a lower value. The old adage, "a light that burns twice as bright lasts half as long" sort of applies here. So a trade off between brightness and power consumption is something to watch.

Viewing Angle

CRT monitors are viewable from almost any angle. That is to say if your view is not blocked by the curve of the screen or the surrounding plastic frame. TFT LCDs have a narrow focus and therefore can only be viewed from inside a certain arc of angles. As the technology improves, this arc is being improved. This should not have any affect on the primary user of the PC, as they should sit facing the display. But if you like to have bystanders watching you achieve the ultimate score on puzzle bobble or you are trying to show off to your girlfriend your best trick in Tony Hawks pro skater, then you may have some issues (and they also might not be able to see the monitor ;-)

Analog vs. Digital connectors

More and more graphics cards are coming equipped with DVI connectors. But should you get a display with a DVI connector, and analog connector, or one of each?

The advantage of a DVI connection over the analog is that the DVI connection allows for lossless transmission from the computer to the display. Signal noise, for instance, should not be a concern with the DVI connection (no more hum bars on the monitor when the vacuum is being used). It also provides support for much higher data rates which are needed for the larger diplays (such as cinema screen size displays). Currently, no other advantages of the DVI connection specification are being exploited. If you would like to know more on this subject go to the Digital Display Working Group (DDWG) who developed the specification.

What To Look For When Buying

As mentioned earlier, Response Times are the primary concern of any TFT LCD screen. Viewsonic is advertising their VP201s monitors as having Response Times (Pixel Response, Video Response) that are fast enough to present "Realistic, artifact-free 3-D gaming." These monitors have a "blistering 16 millisecond (16ms) Response time." Hitachi also advertises their CML174B and CML 175B LCD monitors with Response Times of 16ms "enabling smoother computer video, animation and gaming movement." Samsung goes one step better with their 172X LCD monitor that sports an amazing 12ms Response Time.

Next, be sure to select a screen that has a native resolution that meets your needs. That is to say, if your system can only play games at 800x600 then buying a 2048x1536 monster display wont give you any advantage and will almost certainly do more to hinder your game playing and your enjoyment of it.

Check the dot pitch measurement and make sure you are comparing like-for-like if you are looking at more than one display, especially from different manufacturers.

High contrast and high brightness, but low power comsuption is a very good combination because this will give you impressive visuals and your display will hopefully last longer.

Other, smaller, concerns (like the price) I will leave to personal preference. A TFT LCD that satisfies all of these criteria will hopefully do justice to your game visuals and give you the gaming experience that you desire.