Hi GT! Yesterday we were picking out Silent PC components , and today let’s talk about such a thing as monitors. Reviews of various displays appear both here and on resources that are 100% devoted to iron, and they are often full of incomprehensible pictures, graphs and complicated words in the conclusions.
Let’s try to figure out what’s important, what’s not important, what’s wrong with some research methodologies, and how to choose a monitor in a crisis in general.
Inside the monitor there may be any matrix, even TN, even IPS with any letters before and after (like AH-IPS), even PLS or any combination of *VA (PVA, AMVA, MVA). The point is the same: each dot consists of three sub-pixels: red, green and blue. How the “shutters” of liquid crystals are located and how they are controlled determines the type of matrix, and with it – its characteristics. We will not go into these details now, otherwise the article can be read until tomorrow. In a nutshell: TN-matrix has the highest speed of “switching” from one state to another, but there are problems both with complete “switching off” light transmission, and with precision of rotation of crystals. IPS has solved these problems, but the matrix uses much more complicated and expensive structures, and to control it you have to use higher voltages, due to which IPS wins in picture quality, but works much slower than TN. A *VA is a kind of compromise between speed and color rendering accuracy. *VA matrices have excellent black color, fairly high response speed, but unfortunately there are some limitations in the area of horizontal viewing angles.
Charts and specifications
When you look at any monitor review (take our review “frameless” Eizo), there are usually several characteristic pictures in it :
Color coverage triangle
Together they show how accurately the monitor reproduces colors. I want to point out right away that “accurately” is a very elastic term. First of all, “accurately” depends on what we take as a reference point. If you take the common sRGB color gamut (in which all Web-design and 99% of other hardware works), the results will be the same. If we consider AdobeRGB, then you are in for an unpleasant surprise – this color space is rarely used (mostly for expensive printing), and in everyday use on Windows you will get a nightmare on elm street (red faces) in all applications that do not know how to work with AdobeRGB.
Second, “exactly” depends on the signal source. If your monitor can display 8 or 10 bits per channel, but the signal source is, for example, 6-bit, of course accuracy will suffer. True, the situation on the market now is usually the opposite – many monitors have a 6-bit matrix with FCR (Frame Rate Control), which shows two “intermediate” frames to get the desired eight-bit color.
To buy a “home” monitor, relatively well cope with all tasks: work with graphics amateur level, toys, movies and everyday use should pay attention to the following characteristics.
Contrast ratio and how it is achieved
The coefficient itself is contrast ratio indicates the maximum ratio of the brightest to the darkest of the colors displayed by the monitor. It is easy to calculate: we take the ratio of the brightest (i.e. white) to the darkest (black) color, divide one by the other and get some value, for example 260:1. Unfortunately, manufacturers often cheat by drawing “dynamic” contrast on boxes (black is measured at minimum brightness and white at maximum brightness), but we are interested in static contrast measured at a certain brightness. Generally, measurements are made at 100% brightness or 66% brightness, depending on the measurement technique.
Now briefly about the important stuff. As it is clear from the formula (max. brightness / min. brightness) you can achieve good contrast in two ways: by increasing the numerator or decreasing the denominator. It is much easier to install bright backlight LEDs than to put a good quality matrix with deep black color. So if your monitor has a decent 1200:1 screen, have a closer look at the maximum brightness: sitting in front of a panel with 400-500 nits is not much fun.
Normal is about 220-250 nits and a contrast ratio of about 800-1000:1.
What this kind of gamma correction is all about is perfectly explained at cambridge in color , just can’t add or take away. For LCD displays, the gamma curve is set by the manufacturer in a built-in calibration table, and can often be changed in the settings between setpoints. Nevertheless, the abstract values indicated in the menu can differ from the “reference” ones quite significantly due to certain restrictions: both technological and marketing ones. The most interesting for the user is not so much the “ideal” 2.2 (you can also live with 2.4 and 2.1) as the closeness of the measured curve to the “reference”: it will allow you to be sure that the monitor does not distort colors and does not change the image contrast depending on the brightness of certain areas. Here is an example of a not perfect, but not bad gamma curve:
The gamma coefficient should ideally be 2.2, small variations in either direction are acceptable. The main thing is that the gamma curve should not differ from the reference, especially in the “middle” of the curve – where the largest number of “working” shades of the monitor is located.
Many manufacturers like to “measure triangles, ” but unfortunately, the “triangle” itself is of little use because it only displays the color gamut at maximum brightness. The real color space looks like a complex three-dimensional figure:
Few reviews compare the full coverage at all brightnesses, and a simple “triangle” can only estimate a portion of the color coverage. However, this information is not 100% useless. If the color gamut is close to sRGB and the monitor’s “triangle” is not significantly distorted relative to the benchmark, everything is more or less fine. If, however, one of the vertices is highly prominent relative to the others, and the shape of the triangle is far from sRGB, the device will obviously “falsify” in the direction of the protruding vertex.
A color gamut that matches sRGB as much as possible is a good thing. At the same time, both 85% and 80% coverage is not a crime, it is important to understand that the “triangle” should resemble the reference as much as possible, then there will be no problems with color distortion. Ideally, the overview should show a three-dimensional color gamut, but few people bother with such measurements.
The standard indicator is. color temperature (so called “daylight”) is considered to be 6500 Kelvin. Values higher than 6500 mean that the monitor starts to “cool” (i.e. goes into the blue color), values below 6500 – the monitor “heats” the colors, showing instead of white and shades of gray, the first yellowish, and then orange shades. The color temperature is easy to correct, the most interesting thing for you as a user is the uniformity of the color temperature. If you have 8000K in the “shadows”, 6500K in the middle segment, and 5000K in the highlights, the “average” is of course 6500K. The trouble is that it is difficult to work with such a monitor, so the main interest is the evenness of color temperature – let it be slightly over or underestimated, but all over the coverage is more or less the same. This can also include the uniformity of color temperature over the matrix field. The more even, the better.
It’s the uniformity of color temperature that’s more important than its numerical value. You can fix the temperature, but the unevenness is very hard.
Calibration and adjustment
Often a review may say that a number of indicators can be improved by resorting to calibration. Color adjustments can be made in two places: on the monitor itself and on the graphics card. It is the display settings that are preferable. The professional and expensive models have 10 or 12 digits LUT (rectification table) for each of the controllable values and the calibration allows to tune the monitor more accurately and without problems. The LUT of a video card is usually eight-bit, which means that you only have 255 values, and strong adjustments will result in a significant reduction in the number of colors displayed.
There is one more important note. Correction can only be done with a colorimeter or photospectrometer. We use ColorMunki Photo whose price tag is generally quite far from humane, especially if you choose a monitor on a fairly modest budget. The most inexpensive and adequate option is. ColorMunki Smile – costs about eight and a half thousand rubles. Perhaps there are models on the market that when calibrated become significantly better than their competitors with a price tag of 8, 500 rubles more, but experience suggests that such a thing is possible only in the professional segment. There, people usually already have colorimeters and a clear understanding of what they need, and +- 10, 000 rubles does not play a major role.
Calibrating your monitor allows you to “pull” it to a level of reliably reproducible colors, but requires special equipment and a clear understanding of what you are doing and why. If you’re buying “just an all-purpose monitor for home”, it’s better to look at models with good factory settings than to take a “potentially good” monitor for tweaking.
In addition to the color gamut and monitor characteristics, it is worth paying attention to the way the backlighting is realized. Its unevenness is usually well shown, and if the review does not say anything very bad about it – in general you can “drop it” and not bother with this topic. It is better to pay attention to the NIR characteristic: there are still models that unpleasantly “flicker” backlighting at a certain brightness, which makes eyes tired, and setting a comfortable level of backlighting is sometimes difficult. Ideally – full Flicker Free backlighting.
Hopefully, these tips will help you adequately evaluate the performance of monitors and properly choose your gadgets Remember that the monitor directly affects your eyesight, so it’s definitely not worth choosing irresponsibly. Ask us your questions, we will try to answer them all. 🙂