Articles: Monitors
 

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It should be made clear, however, that a simple increase of the monitor’s refresh rate, as they did with CRT monitors to avoid the flicker, is not enough. It is necessary that all the frames are unique. Otherwise, the frame rate increase is useless.

This would produce a funny side effect in games. In most new 3D games a speed of 60fps is considered good even on up-to-date graphics cards, and an increase in the refresh rate of your LCD monitor won’t affect the fuzziness until you install a powerful graphics card, capable of running the game at a speed corresponding to the monitor’s refresh rate. In other words, the image fuzziness effect in games will depend on the graphics card after LCD monitors with a real refresh rate of 85 or 100Hz appear, although we’ve all got used to regard the fuzziness as depending only on the monitor’s properties.

It’s more complex with movies. Whatever graphics card you install, there is still 25fps, or 30fps at most, in movies. Thus, an increase in the monitor’s refresh rate won’t affect the fuzziness effect in movies. There is a solution: when reproducing a movie, additional frames can be created that would be the average of two sequential real frames. These frames are then inserted into the video stream. This approach will help reduce fuzziness even on existing monitors since their actual refresh rate of 60Hz is two times the frame rate of movies.

This is already implemented in the 100Hz LE4073BD TV-set from Samsung. It is equipped with a DSP that is automatically creating intermediary frames and inserting them into the video stream in between the main frames. On one hand, the LE4073BD indeed exhibits much lower fuzziness than TV-sets without such a feature, but the new technology produces a surprising side effect: the picture looks like soap operas with their unnaturally smooth movements. Someone may like it, but most people would prefer the minor fuzziness of an ordinary monitor to the new “soapy” effect, especially as the fuzziness of today’s LCD monitors in movies is already on the brink of being perceptible.

Besides all these problems, there will be purely technical issues. Thus, an increase of the refresh rate above 60Hz will call for the use of Dual Link DVI even in monitors with a resolution of 1680x1050 pixels.

Summarizing this section, I want to emphasize three main points:

A)  For LCD monitors with a real response time of less than 10 milliseconds, the further reduction of the response time brings a smaller effect than expected because the persistence of human vision becomes a factor to be accounted for. In CRT monitors the black period between the frames gives the retina enough time to “forget” the previous frame, but there is no such period in classic LCD monitors – the frames are following each other continuously. Thus, the further attempts of the manufacturers to increase the speed of LCD monitors will be about how to deal with the persistence of vision effect rather than about how to lower the specified response more. By the way, this problem concerns not only LCD monitors but also any other active-matrix technology in which the pixel is alight continuously.

B)  The most promising technology at the moment is the short-term turning off of the backlight lamps as is implemented in the BenQ FP241WZ. It is rather simple to implement (the only downside is the necessity to use a large number and a certain configuration of backlight lamps, but it’s a solvable problem for monitors with long screen diagonals). It is suitable for any type of the matrix and doesn’t have serious flaws. Perhaps the refresh rate of the new monitors will have to be increased to 75-85Hz, but the manufacturers may solve the problem of flickering (noticeable on the above-mentioned FP241WZ model) in other ways, so we should wait for other models with backlight blanking to appear.

C)  Generally speaking, today’s monitors (on any matrix type) are fast enough for a majority of users even without the mentioned technologies. So you should only wait for the arrival of models with backlight blanking if you are absolutely unsatisfied with the existing monitors.

 
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