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A lot has happened in the display area lately.
Finally, OLEDs are no longer only found in smartphones or televisions, but also in monitors.
Although LCDs will remain the standard for the time being, manufacturers are already reacting to the new competition.
There are a few things to consider when buying monitors.
After LG ventured into small OLED televisions - here they have now reached 42 inches - the Korean panel manufacturer now apparently wants to produce OLEDs with even smaller diagonals.
They will probably be 27 inches, i.e. a diagonal of almost 70 centimeters.
PC monitors with such panels would be particularly interesting for photo editing and video editing.
At the end of 2021, LG will present the first OLED monitor for image processing.
The 31.5-inch OLED Pro 32EP950-B initially cost around 3250 euros, but you can now get it from 2100 euros.
The 4K monitor does not yet use an in-house LG panel, but one from the Japanese OLED specialist JOLED.
With the ProArt PA32DC, Asus has a counterpart with the same panel in its range that costs a sporty 4000 euros.
Luminance, color gamut, calibration
At 250 cd/m2, the current OLEDs are less bright than comparable LCDs (from 500 cd/m2).
On the other hand, new OLEDs should hardly suffer from the so-called burn-in, which is particularly important for PC monitors with their rather static content.
When it comes to the given color space, there is often talk of 140 percent sRGB or 98.5 percent Adobe RGB.
However, such information is not very helpful, because reproducible image processing is only possible if a display exactly covers a selected color space.
The information on the color deviation in ΔE is therefore more important.
The only theoretically achievable ΔE of 0 would mean absolute agreement.
In practice, deviations from ΔE < 1 are hardly noticeable to the human eye;
Color distances between 1 and 2 only when looking very closely.
Therefore, an upper limit of ∆E = 2 applies to colour-accurate work.
Professional monitors are usually hardware calibratable, correction values are stored directly in the monitor's look-up table.
Inexpensive devices only allow software calibration, in which corrections are instead stored in the ICM profile and integrated via the graphics driver.
The advantage of hardware calibration: The correct color display on the screen remains independent of the connected PC and the application software used.
Some devices already have the necessary color measuring device (colorimeter) integrated.
Professional monitors can also differentiate 10 bits per color and thus 1.07 billion mixed colors.
Your look-up table (LUT) with the color values determines how precisely the image transferred from the graphics card is further processed internally.
Monitors for image processing work with at least 14-bit LUTs, better ones with 16-bit.
So-called 6-bit panels should be avoided if you view or even edit photos or videos on the screen.
These can only output 262,000 colors on the screen and therefore produce graduated color gradients.
However, the lower color resolution is not a problem for most office work.
LCDs with mini LEDs
The LCD technology, which has already been declared dead several times, is rearing up once again, and its manufacturers are countering the developments in OLED panels with a finely dimmable backlight made of small mini-LEDs.
Thanks to so-called Full Array Local Dimming (FALD) with over 1000 dimmable zones in some cases, they should catch up with the high-contrast organic displays.
With the OLED, however, each individual pixel lights up itself and corresponds to a mini-LED segment - a 4K OLED with 3840 × 2160 pixels has a good 8 million zones.
But even if they lag behind in a direct comparison, LCDs with a good FALD are impressive.
So far, however, they have also been based on the price of OLEDs.
The 32-inch AOC Agon Pro PD32M in Porsche design with 1152 dimmable zones costs 2100 euros, the counterpart Elite XG321UG from Viewsonic should even cost over 3000 euros.
In the same size, but with half the number of zones, you can get the ProArt PA32UCR-K from Asus from 1400 euros.
The number of LED groups that can be controlled in a targeted manner has a direct effect on the price of the device, but the technology is likely to become cheaper in the near future.
Basically, only image editors or gamers need the very finely dimmable backlighting on the LCD.
We would currently not count desk-size monitors with fewer than 512 zones as FALD devices.
Sony's gaming monitor Inzone U27M90 only has 96 separately dimmable zones (12 × 8), which is not fine enough: the mouse pointer creates an ugly aura on dark backgrounds.
ALLM, VRR and speed for gamers
Short panel switching times are crucial for gamers, as is a low latency between mouse movements, the graphics card output and the image display on the monitor.
Many devices accelerate the image change with a so-called overdrive, which sometimes overdoes it with the target brightness.
The display then creates double contours and color fringes on moving edges.
On the other hand, if the panel takes too long to change the brightness, the image becomes blurred.
The switching times given in data sheets often refer to excessive overdrive settings.
The switching times that can actually be used are therefore usually somewhat higher.
Current LCDs achieve minimum switching times of around 4 milliseconds – everything below that has to be accelerated using overdrive.
This does not apply to OLED panels, they are extremely fast with switching times of less than 0.5 milliseconds.
However, this must also apply to the monitor electronics: With monitors for image processing, despite the fast OLED panel, 60 Hertz often ends.
Any tearing of the image, jerks and latencies can be reduced by variable refresh rates (VRR): The monitor accepts the image signals exactly when they arrive - and not only when it has completed the construction of a complete image.
AMD calls it VRR FreeSync, Nvidia calls it G-Sync, VESA speaks of Adaptive-Sync, Intel's integrated graphics also support VRR.
You need at least DisplayPort version 1.2a or HDMI version 2.1 at the signal input.
Good gaming displays run between 1 Hz and 360 Hz in sync with the graphics card output, cheap ones only manage between 48 and 60 Hz.
In favor of OLEDs are their seamlessly quick changes in brightness, but the display diagonals that have been available so far.
But while 1.07 m (42 inches) and even more so 1.20 m (48 inches) are usually too big for the office desk, Asus, Gigabyte and LG offer OLED monitors in this size for gamers;
the panel comes from LG.
With Samsung Displays, another producer of OLED panels entered the ring this year and immediately opted for smaller diagonals: In March, Dell debuted the 34-inch Alienware AW3423DW gaming monitor with Samsung's QD-OLED technology.
Now Samsung is following suit: The Odyssey OLED G8 G85SB is also aimed at gamers and, like the Dell counterpart, has a 21:9 format with 3440 × 1440 pixels.
It should go on sale in mid-December for around 3000 euros.
Philips recently introduced its new gaming brand Evnia.
It includes both a 42-inch monitor with LG's OLED technology (42M2N8900) and a 34-inch monitor with Samsung's QD-OLED technology (34M2C8600).
Both devices are scheduled to hit the market in January 2023 and remain under the €2,000 mark.
In addition, Philips has developed a 34-inch LCD with FALD backlight and 1152 dimmable zones.
The Evnia 34M2C7600MV uses a curved VA panel with 3440 × 1440 pixels and is expected to be available later this year for around 2000 euros.
The 27-inch LCD variant without FALD is called the Evnia 27M2C5500W and only costs a fraction of this at 580 euros.
Office workers need space
The high contrast range of displays with OLED or FALD technology is particularly important when playing photos and videos.
It is unimportant for displaying Excel sheets, PowerPoint presentations or texts.
That's why you can use the cheaper monitor with conventional LCD technology for office work, surfing and e-mailing.
The resolution should be a deciding factor here: Full HD resolution with 1920 × 1080 pixels results in a pixel density of just 82 dpi on a 27-inch monitor.
The display surface then appears up close like a fly screen.
The 27-inch monitor should have at least WQHD resolution with 2560 × 1440 pixels and 109 dpi - the pixel density of 100 dpi should only be undercut in exceptional cases.
If you need more space, you can either place two 16:9 screens next to each other or use an extra wide monitor with 21:9 or even 32:9 format.
Two individual monitors are usually the cheaper option, but there are no dividing lines or seams on the extra-wide large screens: Windows can be distributed more freely on the screen and there are no problems with different display heights.
The ConnectedView screen budy tested by »c't« is a simple remedy for crooked displays whose edges should end at the same height.
Extra-wide monitors usually have a 21:9 or 24:10 format.
You can currently find 34-inch models with 3440 × 1440 pixels and 21:9 format from 380 euros and 38-inch models with 3840 × 1600 pixels in 24:10 format from 800 euros in shops.
The wider the monitor, the more likely it is to have a curved display: it is more comfortable to work with.
Curved displays are only out of the question for image processing: Because the curvature is accompanied by slight optical distortions, one would possibly compensate for this in the image and thus incorporate a distortion.
