First, the matrix has viewing angles. The problem of the early 16msec matrices was in awfully small viewing angles, which prevented the user from working normally. Even sitting motionlessly and looking at the center of the screen perpendicularly you could see that the top of the screen was much darker than its bottom, and colors were yellowish at the sides. By the way, this thing – a strong darkening of the image when it is viewed from below – unmistakably distinguishes a TN matrix from the other types, which have no such defect.
Of course, some improvements have been made since. The horizontal viewing angles are now wide enough for you to sit before the screen with your friend without complaining at the “impure” white color; the vertical angles aren’t provoking any big discomfort too, although the vertical irregularity of the screen brightness is still visible even in the best samples. Unfortunately, the manufacturers of monitors on TN matrices, trying to match the competitive matrix types in this parameter at least on paper now often declare the viewing angles measured by the fall of the contrast ratio to 5:1 rather than to 10:1. This way TN matrices acquired 160-degree angles into their specs, without any real improvements. I want to warn you once again and remind you the above-described method of measuring the viewing angles. A true specified angle of 140 degrees doesn’t mean that its defects are only visible “when you are looking at it from under the desk” or “dance before it when working” as some users think, because visible distortions of the image appear much sooner before you reach those specified angles. The number “140 degrees” means you’ll see strong image distortion when looking at the screen at such an angle. For example, the vertical irregularity of brightness is visible in a TN matrix whatever position you choose before the monitor, so if this matters to you, a monitor on a TN matrix would be the worst choice you could make.
Then, the contrast ratio of TN matrices is not ideal, either. Although many manufactures declare a contrast ratio of about 500:1, the real contrast ratio seldom exceeds 300:1, some rare samples getting as high as 400:1. In practice this means that you can’t get a good black color on a TN-matrix monitor, and the black background on the screen will look highlighted if you’re in a dim room (for example, when you’re watching a movie). I should note, however, that the contrast ratio of matrices depends heavily on the manufacturer. For example, the latest matrices from Samsung have a standard contrast ratio of 300…400:1, while matrices from Chunghwa Picture Tubes (CPT) often have a deplorable contrast, so monitors on them can only be recommended as inexpensive office devices.
By the way, another drawback of TN matrices is that if a thin-film transistor crashes, there appears a bright dot on the screen, as pixels in TN matrices let light pass through in their inactive state. Such bright dots are more annoying than black pixels, especially if you’re intending to use the monitor at home, i.e. in the evening, for watching movies or playing games.
Next, the color reproduction of matrices of this type is far from perfect, too. All fast matrices are 18-bit, i.e. they employ Frame Rate Control to display all 16.2 millions of colors, but the colors of TN matrices are anyway bad – they are faded, unimpressive, rather far from natural ones, which makes TN matrices a bad choice for working with colors even amateurishly.
Thus, the small response time turns to be not just the main, but the only advantage of TN matrices. All of their other parameters are rather average. Monitors with matrices of that type suit for playing games and watching movies and for routine office work, but professionals may want to consider other types of the matrix. Unfortunately, this means limiting yourself with monitors with a diagonal of 19” and bigger, since the majority of 17” models have TN+Film matrices now.