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Manufacturer: ViewSonic
Min OS X: Any Version

ViewSonic VP171b
March 31, 2004 | Johan Hansén

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The monitor may be one of the most important components of a computer, but it is still one of the most overlooked. Many people are satisfied with having a monitor that works, but there’s a huge difference between a monitor and a monitor. The biggest difference can be found between the two main types of monitors: the classic, bulky Cathode Ray Tube (CRT) monitors and the newer, thin Liquid Crystal Display (LCD) monitors. LCDs are almost as old as portable computers, but recently, they have become more and more common on desktop computers. The reasons for using an LCD instead of a CRT are many. The most obvious is that an LCD takes a lot less space on the desk. It also consumes less power and emits less radiation than a CRT monitor. A LCD also produces a sharper image with higher contrast than the average CRT.

So why do people still use CRTs? Well, one major point has been the price. Even though LCDs have decreased rapidly in price, they can still cost twice as much as a CRT, depending on the size of the displays. LCDs are sensitive to the viewing angle, causing colors and contrasts to change depending on the vertical or horizontal angle the monitor is being viewed at. Another factor, the most important to gamers, is an inherent limitations of an LCD display. While a CRT uses a photon cannon to project an image on to a grid at the front of the display, a LCD consists of three layers of liquid crystals — three crystals per pixel on the screen. These crystals can take on different hues of red, green and blue respectively and when looked upon they will give the impression of one pixel at any color imaginable. This means that an LCD only has one possible resolution, determined by the number of liquid crystals. A CRT can change between a multitude of resolutions and all resolutions below the recommended usually look sharp and crisp. On a LCD, you have one native resolution, and all other resolutions have to either be cropped down with black space surrounding it, or scaled up to fill the whole screen, with the additional pixels extrapolated mathematically by the display. This never looks as sharp as on an CRT, and the earlier can give you a mightily small image on a large display when playing old games with low resolutions.

The relatively high response times has also kept most gamers away from LCDs. The response time is the time it takes for an individual pixel on the screen to go from black to white and back again. In the early days of LCDs, the response time could be rather long, leaving traces of the movement on the screen, called ghosts. The response time is comparable to a CRTs refresh rate, which represents the number of time per second the whole screen is redrawn. On a modern CRT the refresh rates usually are in the range 75-120 Hz (or redraw/refresh per second). Since the whole screen is redrawn at every single pass, there is no ghosting.

Technology has advanced enough that the monitor manufacturers dare to claim that their LCDs are now suitable for gaming, since they’ve been able to get response times lower than 20 milliseconds (ms). That translates to 50 black and white cycles per second (which actually would be 100 changes per second). One will have to bear in mind that this is from black to white, and not between different hues. Usually it’s the switch back to black that goes fast and the changing of hues that goes slower. The response time is to be taken with some reconsideration, since the manifaturers might press the display to get as low response time as possible but still have it slow between other hue changes. Still, most displays with a refresh rate of 20ms or below are usually targeted towards gamers as well. The Viewsonic VP171b tested here has a response time at 16ms (62.5 times from black to black per second). Is is sufficient for gaming?


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