We ran a number of diagnostic tests on the Asus PG221 to assess its image quality and performance. The pictures you see below are but a sampling of the tests built-into Lavalys' Everest Ultimate Edition. Everest Ultimate Edition in particular displays over 40 patterns to test a monitor's capabilities. Some are designed with CRTs in mind, but many of the patterns and screens are useful to gauge an LCD's ability to reproduce even colors across the entire panel to see how it handles a wide range of colors with a myriad of gradients.
To our eyes, the Asus PG221 made it through all of tests without any major issues. In all of the calibration screens and grid tests, the PG221 produced distinct gradients and sharp, perfectly straight grids in every section of the screen. In all of the text reproduction tests, the PG221 also did well, producing clear, sharp text regardless of the color combinations used.
Gradient fills, various gamma levels, and HSL color palettes were all reproduced very well. We also found that in the solid color tests, the PG221 produced even brightness from edge-to-edge. Some LCDs suffer from uneven distribution of their back-lighting, but this was not the case with our PG221 sample. We should also note, however, that this issue is barely perceptible during "real-world" use and is only a problem when a single, relatively dark color is being displayed across the entire surface of the panel.