We test desktop monitors of all stripes here at PCMag.com, from barebones budget screens to moderately priced mainstream displays to high-end, big-screen Ultra-High Definition (UHD) models that cost thousands of dollars. Every monitor we review is subjected to a series of image quality and performance tests that we use to draw a comparison to other monitors in the same class, which in turn helps us to assign a rating to each monitor. Read on to see how we test monitors.
All monitors are tested in an out-of-the-box state, which means we do not calibrate the monitor or tweak color settings. However, in order to ensure accurate, repeatable testing results, we use the monitor’s Standard picture mode while testing and turn off all digital processing settings, such as Dynamic Contrast Ratio, Adaptive Contrast, and Color and Black Level enhancers.
Our monitor testbed PC has an Intel Core-i7 CPU, 16GB of DDR3 RAM, a Blu-ray drive, and an Nvidia GeForce GTX Titan graphics card. We use an HDMI or DisplayPort signal when possible and a DVI signal if neither of the above-mentioned ports are available. We also use a Sony Playstation 3 console to test gaming performance and a Leo Bodnar Lag Tester to determine input lag. Color accuracy is measured using a DataColor Spyder4 PRO colorimeter, along with SpectraCal’s CalMAN 5 software and DisplayMate’sMultimedia Edition diagnostic software.
To test color accuracy we let the monitor warm up for at least 30 minutes and use DisplayMate’s red, green, and blue Color Purity samples as reference colors. Using the Spyder 4 Pro and CalMAN 5 software we measure the monitor’s color accuracy, compared with the CIE 1931 standards. The results are captured and plotted on a CIE 1931 XY chromaticity chart, with our measurements represented by the colored dots and the CIE coordinates represented by the boxes.
We use the DisplayMate 64-Step Gray-Scale test to see if the panel can display every shade of gray, and if each shade gradates evenly from light to dark. Here, we also look for tinting in the middle of the gray-scale, clipping (whitewashed light grays), and crushed blacks (a sudden transition to black rather than a gradual transition from gray to black). We then use a series of test images and a Blu-ray movie with lots of dark scenes to see how gray-scale performance effects highlight and shadow detail.
We test energy efficiency using a Kill-A-Watt meter and a static image with lots of white in the background, as well as a good mix of colors and text. We record the monitor’s power consumption while operating in Standard Picture mode, and then measure it again while operating in Eco or Power-Saving mode. If a monitor does not have a power-saving mode, we compare Standard mode with Movie mode, which uses relatively low brightness and contrast settings.
Viewing-angle performance (how the display looks when viewed from top, bottom, and side angles) is tested by looking for changes in luminance and color fidelity at various angles. We use the same image that we use for energy efficiency, and look for faded blacks in text and color shifting (where whites appear tan, and red colors may take on a brownish tone). We also check for dimming and a washed-out image, both of which are common characteristics in low-cost Twisted Nematic (TN) panels. If a panel shows any of the above signs, we report how far off dead-center (in degrees) we have to move before noticing a change.
For business monitors, we evaluate text readability using the DisplayMate Scaled Fonts test. We look to determine if the panel can display small fonts legibly, and check each letter for sharpness and definition around the edges. We start with the smallest font in the test and move upward in size if the panel cannot display the smaller characters correctly.
Gaming performance is gauged using real-world PC games played at the monitor’s highest resolution. Here, we look for motion artifacts such as blurring and ghosting (a faint double image that usually occurs in monitors with a high-pixel response). Currently, we use Aliens vs. Predator for the PC and Burnout Paradise for the PS3 console. We also test input lag, which is the amount of time it takes (in milliseconds) for the monitor to respond to a command from your keyboard or game controller. The input lag is measured using the Leo Bodnar Lag Tester.