Picture quality is one of the most important aspects of a monitor. Like with TVs, we define picture quality as the ability of a monitor to display an image as closely as possible to the content creator's intent. This usually means great blacks and accurate colors, visible from any position or lighting condition.
We test many different aspects of picture quality, and combine their respective scores to arrive at a combined picture quality score. Note that you shouldn't look just at this score, as some of those tests only matter in certain viewing conditions. For example, contrast, black uniformity, and local dimming only really matter if you are using your monitor in a dark room.
Monitors have less variation in picture quality than TVs. The majority of monitors we've tested deliver decent overall picture quality, and most of them have very similar strengths and weaknesses.
Our contrast ratio tests verify the ratio between black and white on a monitor. A higher ratio means that the monitor can produce deeper, darker blacks; whereas a lower ratio means blacks look gray. As contrast is one of the most important factors in picture quality, this test has a very high weight. It is especially important if you watch a lot of dark content in a dark room.
Monitors are typically grouped into two: VA, and IPS/TN. The majority of VA monitors tend to have contrast ratios over 2500, whereas most TN/IPS monitors vary between about 600 and 1500.
Our local dimming tests check to see how well a monitor can increase contrast by dimming, or turning off the backlight on certain portions of the screen. We use a local dimming video pattern to compare multiple monitors side-by-side, and assign a score subjectively.
Very few monitors support local dimming, and most people shouldn't consider this factor when purchasing a monitor, so this test isn't weighted as highly as for TVs.
Our peak brightness tests evaluate how bright a monitor can get. In SDR, this test demonstrates how well a monitor can fight glare in a bright room. The brighter a monitor can get, the better it can overcome reflections or glare.
Our viewing angle test evaluates monitors for how well they retain picture quality when viewed from the side. This doesn’t matter for people who sit at a comfortable distance directly in front of their monitor, but if you like to sit close to the monitor, or often share your screen with some one else, a good horizontal viewing angle is a must.
The vertical viewing angle test evaluates monitors for how well they retain picture quality when viewed from above or below. This usually isn't much of an issue for most people,
Our gray uniformity tests evaluate monitors for how well they can display a solid gray screen. The results of this test apply to pretty much all solid colors you can see on the monitor, which means it’s important for any uniform scene, including browsing the web.
Gray uniformity defects tend not to be noticed by most people unless solid colors are displayed, so this weight a little bit less in this category.
Our black uniformity testing checks to see how evenly a monitor can display solid black across the screen. This is an important test for dark scenes, as poor uniformity could mean some parts of the scene are not lit in the manner intended by the source, thus affecting the kind of mood that is established.
This isn’t that important for people who use their monitor in a room that has lights on, but it’s quite important if you plan on using it in a dark room.
Our pre calibration test evaluates how accurately the monitor can produce color before a full calibration. How well a monitor can reproduce color affects the appearance of everything your monitor displays, so it’s something worth considering when making a purchase.
Most people don’t see much difference if color is a little bit off, so this test doesn’t hold much weight in our scoring.
This test evaluates the monitor's ability to display color accurately after we have performed a full calibration with a colorimeter.
This test is not that useful for most people, as very few people professionally calibrate their monitors. However, it is an indication of how accurately the monitor can display colors.
Our color gamut test evaluates the range of colors a monitor can display. We test coverage of the sRGB color space, which is used by the vast majority of SDR computer content, as well as the Adobe RGB color space, which is mainly used for professional photo and video editing. Most monitors can display almost all of the sRGB color space,
On monitors that support HDR, we repeat these tests with the DCI-P3 color gamut and the Rec. 2020 color gamut. Very few monitors
Our Image Retention test evaluates how long a monitor keeps displaying a ghost of an image once the signal is no longer there. The longer an image lingers on the screen the worse experience you will have.
Like with TVs, our gradient test evaluates monitors for how well they can display gradual differences in color, which is important for reproducing subtle details in color. More detailed color is especially important for a good HDR display.
We also check the color bit depth that the monitor can display, usually either 8-bit or 10-bit. We don't differentiate between true 10-bit or 8-bit panels, and panels that have a lower bit-depth, but use dithering (FRC) to approximate a higher bit depth.
Color bleed is an undesirable artifact that appears on some displays, causing discolored stripes to appear on the screen, both vertically and horizontally. Essentially, large elements of uniform color are displayed with a faint "ghosting" effect that extends past their boundaries.
We test for both horizontal and vertical color bleed. This used to be a fairly common issue, but in recent years it has all but disappeared. On the few monitors that we've tested that showed some signs of color bleed it is almost completely unnoticeable with normal content, and most people shouldn't worry about it.
Our reflections tests evaluate monitors for how reflections will look on the screen. This is especially important if you have a lot of windows in the room, or a lot of lights, which is usually the case for an office setting. Although the majority of monitors have very similar reflections handling, some are better than others.
Unlike TVs, we don't currently measure the actual reflectivity of the monitor, this score is instead assigned subjectively, by comparing the monitor with other similar models.