What to keep in mind when choosing our monitor
What should be kept in mind when choosing our monitor? The first parameter to consider is its size. The size of a screen is expressed in inches (equal to 2.54 cm), a measure that refers to the length of its diagonal. The ratio between the two sides can be the traditional 4:3 or “widescreen” 16:9 or 16:10.
The maximum resolution, instead, defines the detail rendering capability and is obtained by multiplying the horizontal pixels by the vertical ones. The pixel, short for “picture element,” is the single point on the screen, and a matrix of pixels creates an image. As with mosaic tiles, the higher the number of pixels, the more detailed the final result will be, but it should not be forgotten that when using extreme resolutions, the on-screen characters become so small as to be almost unreadable. Therefore, those who use the computer mainly for office work should avoid purchasing a screen with ultra-high resolution.
The response time, measured in milliseconds, indicates the speed at which the same pixel switches from black to white to black or between different shades of gray. In moving scenes, a monitor with very fast response times has the advantage of not creating annoying ghost images, but at the expense, however, of color quality, which will be lower. Many panels use “Overdrive” technology to reduce response time, but even with this solution, color quality degrades slightly.
Brightness (or luminance) and contrast are two other fundamental parameters. Brightness is measured in Nits (candelas per m²), and is often very high to achieve an increase in the dynamic contrast of the monitor. The image will therefore be bright and attractive, but over time can cause eye strain and harm vision. Contrast is measured in Lux and is obtained by dividing the maximum intensity of white by that of black. Some manufacturers claim that the higher its value, the sharper the image will be, but this is not true because contrast obtained by increasing brightness ends up burning many details, both in highlights and shadows. It is no coincidence that in photography and graphics, two fields in which sharpness is a decisive factor, these values are quite contained: contrast is about 220:1 while for brightness one “settles” for 110 Nits.
Panels
Compared to CRT monitors which more reliably reproduce original colors, LCD panels do not always meet expectations in color rendering; if a good tone match is needed, one must be willing to spend at least €700 for a good 20” monitor. Everything depends on the type of panel the screen uses.
Entry-level products use TN (Twisted Nematic) technology; it’s inexpensive, generally has a low response time and is thus suitable for multimedia computer use, but it has low contrast, blacks are shallow and color reproduction is not very faithful. A TN screen displays 16.2 million colors, but in reality only 262,000 interpolated. In this type of panel, dead pixels appear white while defective ones are colored, and the viewing angle is quite narrow, 160° / 160° (right-left / top-bottom). TN+Film is a TN panel with an added film having a high refractive index that increases the viewing angle to 170° / 160°.
IPS (In Plane Switching) technology panels have a slower response time than the previous ones but higher contrast, more accurate colors, and a viewing angle of 172° / 172°. In IPS panels, dead pixels are black. S-IPS (Super IPS) offers better color reproduction—16.2 million non-interlaced colors—and is faster than IPS. Up to 20”, these are the best panels for photo retouching and graphics.
Professional monitors often use the A-TW-IPS (Advanced True-White IPS) panel, an IPS panel with an added filter that makes whites more natural and increases the gamut, the range of colors perceivable by the human eye. On monitors larger than 24”, there may be the H-IPS panel, which corrects some defects of the S-IPS such as the slight purple tint present at the corners or the almost imperceptible background electronic noise.
VA (Vertical Alignment) technology is a compromise between TN and IPS. MVA (Multidomain Vertical Alignment) panels have better features than TN panels but are inferior to IPS. Contrast, however, is higher compared to both and ensures deep blacks, although this leads to loss of detail in very dark areas. Dead pixels are black and response times are slower than the previous two. P-MVA (Premium-MVA) is an MVA with added “overdrive” technology. Then there’s the PVA (Patterned Vertical Alignment) panel with a wider viewing angle, 170° / 170°, and higher contrast, and its evolution, S-PVA (Super-PVA), ideal for photo retouching and graphics, mainly used in monitors larger than 21”. A screen with this panel displays 16.7 million colors, and up to 68.7 billion representable colors if using a 24” with 36-bit technology. The viewing angle is 178° / 178°, color reproduction is extremely accurate, and “overdrive” technology is often added to speed response times, which are quite slow to ensure excellent image quality.
The SA-SFT (TFT Super-Advanced Super Fine) is finally a very high-level panel intended for image professionals, the only one capable of reproducing up to 105.7% of the Adobe RGB color space and up to 101% of NTSC, with a viewing angle of 176° / 176° and a response time of 20 ms. The cost, of course, is proportional to its quality.
Be the first to comment