| CRTCRT or Cathode Ray Tube monitors are the | | | | RatioThis is the degree of difference between the |
| monitors everyone will have seen before. They that | | | | extremes of light and dark colours. The higher the |
| look like televisions. They range in size from 15 to | | | | contrast ratio, the more detailed the image will be. |
| around 22 Inch, and weight up to 30 | | | | Blacks will be blacker, whites will be whiter, and |
| kilos.AdvantagesGreat value for moneyMature | | | | particularly text on the image will be more vivid. It will |
| technologyGood for graphical detailCan accommodate | | | | usually be written as 500:1 or 250:1Response |
| many different resolutionsDisadvantagesBigTake up a | | | | TimeRefers to just how quickly a pixel can change |
| lot of spaceCost more to run than an LCDLCD | | | | colour. It's measured in milliseconds with 20-30ms |
| TFTLCD or Liquid Crystal Display screens have now | | | | being the normal at the moment. Gamers and people |
| been around a few years, these are the thin screens. | | | | who watch a lot of movies on LCD screens would be |
| Some look almost like a picture frame. You will see | | | | better opting for something with a fast response |
| them referred to as LCD or TFT (TFT being a type | | | | time, around 16ms as this reduces the ghosting |
| of LCD). They start at around 14 inches, and due to | | | | effect of fast motion.When looking to buy a new |
| technological advances bigger LCDs are being | | | | monitor all of the above needs to be considered. |
| produced all the time, 30 Inch are already available | | | | Keep in mind you will be looking at your purchase day |
| with 40 inch on the way too. They weigh very little | | | | in day out for the next few years, so do not cut |
| compared to their CRT equivalent and can be | | | | corners here, buy the best you can afford, your |
| mounted on a wall or shelf with ease.AdvantagesLess | | | | eyes will thank you for it later.Dead Pixel PolicyDue to |
| desk space neededRequire less power to run, more | | | | the difficulties associated with producing LCD screens |
| environmentally friendlyIncreased Viewable area, a | | | | very few brands guarantee a pixel perfect (Class 1) |
| 15"LCD can give the same viewable area as a 17" | | | | product, |
| CRT monitorDisadvantagesViewing angle can affect | | | | and those that do charge a premium for it. |
| image qualityOne native resolutionMore expensive | | | | Most of the screens we sell currently adhere to the |
| than a CRTGeneral Monitor FeaturesSizeHere is one | | | | international standard, ISO 13406-2 and use class 2 |
| area where size does matter, the bigger the monitor | | | | panels. |
| the easier it will be on the eye. You will be able to | | | | It is possible, although uncommon, for a Class 2 LCD |
| open more windows and the text should be easier to | | | | screen to have a small number of faulty pixels. |
| read. Keep in mind the viewable area, all CRT have a | | | | In these cases, this standard deems the screen as |
| smaller viewable area than their size. For Example a | | | | being 'not faulty'.For an LCD monitor to be considered |
| typical 17" CRT will have a viewable area of around | | | | faulty there has to be a certain number of dead |
| 15.8". LCD tends to have the same viewable area, so | | | | pixels:Acceptable malfunctioning pixels by class & |
| a 15" LCD will have a 15" viewable area. Monitor size | | | | type per Million pixels:2 complete pixels constantly |
| (and TVs) are measured diagonally, from the top left | | | | illuminated (a white spot)2 complete pixels not |
| corner to the bottom right hand | | | | illuminated (a black spot)5 sub pixels constantly on or |
| corner.ResolutionResolution is the number of pixels | | | | off or intermittent fault. May blink or show a pixel as |
| displayed on screen at one time, it's usually in the | | | | a base colour (Red, Blue, Green, Cyan, Magenta or |
| format Horizontal x Vertical, e.g.?- 800x600 or | | | | yellow) |
| 1024x768. CRT monitors can display multiple | | | | or, any 2 sub pixel faults within a 5 x 5 block of |
| resolutions easily, while LCD monitors are optimised | | | | pixelsAlso, the faults are cumulative, so if you have 1 |
| for 1 native resolution (They can display other | | | | white spot and 1 black spot per million pixels then this |
| resolutions, but are optimised for 1) the higher the | | | | counts.Native Resolution Pixel Count Example1024 x |
| resolution the more you can get on screen and the | | | | 768 786,432 2 or more dead pixels considered |
| sharper the image.CRT Specific FeaturesDot PitchDot | | | | faulty1280 x 1024 1,310,720 3 or more dead pixels |
| pitch is the distance in millimetres between two dots | | | | considered faulty1600 x 1200 1,920,000 3 or more |
| of the same colour on the screen, it's usually | | | | dead pixels considered faultySo, You can have a 19" |
| measured diagonally and you should be looking for | | | | LCD monitor with a low native resolution where 2 |
| something around 0.26mmRefresh RateThis is the | | | | pixels would be considered faulty, but if it had a |
| number of time the screen is redrawn per second, | | | | native resolution of 1600 x 1200 and therefore had |
| most new monitors should have reasonable refresh | | | | many more pixels, then 2 would not be classed as |
| rates, 75Hz or higher. Some older CRTs had lower | | | | faulty.For any LCD to be classed as faulty it must |
| refresh rates that can cause screen flicker and induce | | | | meet the above requirements, primarily those of the |
| eye strain.LCD Specific FeaturesBrightnessBecause | | | | specific manufacturer. Please contact the |
| LCDs require their own back light to create colour, | | | | manufacturer directly for their current dead pixel |
| brightness is an important factor. It's measured in | | | | policy.Willson Peterson is computer expert and |
| candelas per metre squared or cd/m2, where one | | | | network engineer. He is the author of "How to |
| candle produces a brightness of 1 candela. The higher | | | | backup your computer data" and "Monitor Glossary |
| this number, the brighter the screen.Contrast | | | | of Terms."Click here ==> to visit his website. |