As an example, the picture above shows the monitor’s gamma curves in the Night View mode intended for games that seem too dark to you. The image gets brighter, but not through an increase in brightness, but through raising the gamma curves, mostly of blue and green colors. As a result, the gray balance is distorted, the picture becomes whitish, and details get lost in lights. So, the Night View mode corrects one issue, but provokes another one.
By default in the Standard Mode the monitor has 90% brightness, 80% contrast, 24% image sharpness (when this setting is set higher than 25% there appear light edges around dark lines against a gray background; this leaves an unpleasant impression like a photograph whose author has been too eager in applying the Unsharp Mask filter), and 37% color saturation. To achieve a 100nit brightness of white I selected 68% brightness and 70% contrast. The monitor controls its brightness by means of modulation of the power of the backlight lamps at a frequency of 220Hz.
Color gradients look striped at any settings on this monitor’s screen.
In the Standard Mode at the default settings the gamma curves look good, except for a too high contrast of blue, which is indicated by the characteristic bend of the curve in the top right of the diagram.
At the reduced contrast the blue curve bottoms out but the monitor still continues to display the full range of color tones.
The PG191’s color temperature is set up awfully. The onscreen picture is not warm even in the Warm mode (a temperature of 5400K is a common value for such a mode) and the difference between different levels of gray is as big as 3500K. In the Normal mode the image is obviously too cold. In the sRGB mode the temperature of white is close to the required 6500K, but gray is bluish again.
The picture above illustrates how the difference in temperatures is going to show up in reality. I displayed four squares, from a dark gray to white, on the monitor and then photographed them. Then I made three pictures out of the photo. These pictures differ in the square the white balance was based on. In the first picture it is based on the white square. In the second and third pictures it is based on the light gray and the darker gray squares, respectively. The pictures are shown above, the square the white balance is based on being marked with a checkmark.
If the color temperature of each level of gray was the same, the three pictures would not differ from each other. But here we see that in each picture there is only one really gray square – the one I used to set the white balance. The rest of the squares have some coloring. As a result, you cannot configure the monitor up so that all levels of gray were indeed gray on the screen, without a bluish or yellowish hue, unless you use a hardware calibrator.
Having a specified response time of 2 milliseconds GtG, the monitor proved to have an average response of 3.1 milliseconds GtG in my tests. This is a good result that makes the PG191 one of the fastest LCD monitors available. Its maximum response was 4.5 milliseconds only.
Alas, the fast speed is accompanied with a high level of RTC errors. The error is 15.7% on average with a maximum of over 60%. It means that visual artifacts like white trails behind dark objects or dark trails behind light objects (it is the opposite of the common ghosting effect of LCD matrixes) are going to be conspicuous and even annoying.
The monitor’s brightness and contrast parameters are quite normal as TN matrixes go. Nothing exceptional, but nothing bad, either. Still I have to note that, unlike the PG191, most monitors in this review have a contrast ratio higher than 300:1.
The ASUS PG191 is remarkable for its eye-catching appearance and subwoofer which makes the sound of the monitor’s integrated speakers somewhat more agreeable than that of competing models. From among its technical parameters the excellent matrix speed is the only noteworthy thing. Otherwise, this monitor lacks any exceptional features, but has a lot of drawbacks instead: an inconvenient and strangely behaving menu, a very shabby color temperature setup (and a rather mediocre overall setup of color reproduction), a big RTC error, and a not-very-high contrast. Thus, the PG191 will only make a good purchase for people who care about the appearance of their monitor more than about its color reproduction quality. The high matrix speed cannot be considered a strong argument in favor of the PG191. There are currently a lot of monitors with a specified response time of 2 milliseconds GtG for the customer not to be limited in his choice.