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