The monitor has 100% brightness and 75% contrast by default. To achieve a 100nit white I reduced both brightness and contrast to 56%. The brightness is regulated by means of backlight modulation at a frequency of 394Hz.
The average irregularity of backlight is 9.4% on black and 7.2% on white, the respective maximums being 24.1% and 18.6%. This is quite a lot: the irregularity of black can be easily observed in a dark room. On a dark background you can see brighter areas along the top and bottom of the screen. On a light background the right and left sides of the screen look darker than the rest of it.
Color gradients are reproduced without banding. When the contrast setting is set lower than 40%, dark halftones merge into the same color. When the contrast is higher than 85%, lights are indistinguishable from white.
At the default settings the gamma curves are very close to the theoretical one and provoke no problems with color reproduction. The same is true when the contrast is reduced, but when you set it lower than 40%, the left part of the curves becomes flat and lies on the X-axis of the diagram.
The color temperature setup is good: the temperature dispersion is within 300K in the most popular sRGB and 6500 modes. That’s an excellent result you can rarely see in an entry-level monitor. The temperatures of grays differ more in the 9300 and 5400 modes, but the difference is still within 800K.
The color gamut of the VA903b almost fully covers the sRGB space and exceeds it in the area of greens.
This model is slow even in comparison with RTC-less models. Its response average is 14.9 milliseconds GtG while the longest transition takes 29 milliseconds. The switching from black to white, which is the fastest transition for TN matrixes without Response Time Compensation, is 9.7 milliseconds. This speed is insufficient in the year of 2007 to compete with other monitors.
The brightness and contrast ratio aren’t exceptional but sufficient for the possible applications of this monitor.
The ViewSonic VA903b is a product with average characteristics, which differs from the others with its good color reproduction but has a very slow matrix. It can be recommended for people for whom a natural color reproduction is more valuable than a fast response, although the colors suffer on this monitor due to the typically narrow viewing angles of the TN matrix.