Picture Quality

The KTC OLED G27P6 features a 27-inch widescreen 10-bit OLED panel, manufactured by LG Display, with a native resolution of 2560x1440, giving it a dot pitch of 0.2335 mm (108.79 PPI). For the longest time, 27-inch 1440p monitors were considered to offer an ideal balance of image sharpness, screen real estate, and "manageability" of the resolution when it came to gaming; there are drastically fewer pixels to push compared to 4K resolution, and the image is noticeably sharper than in Full HD. To anyone with limited desk space, I'd still recommend getting a 27-inch 1440p monitor over pretty much anything else, especially if you're into gaming. For content creation and other types of work, you might see it beneficial to opt for a 27-inch 4K monitor, although then you have to swallow a noticeable price hike compared to 1440p models.

As I mentioned in my previous OLED monitor reviews, not everything is unicorns and rainbows when it comes to image sharpness, and the KTC OLED G27P6 is no exception. WOLED panels, like the one this monitor is based on, have a nonstandard Red-White-Blue-Green (RWBG) subpixel layout, which causes fringing around text; operating systems expect a RGB subpixel arrangement when rendering text. Fringing looks like text elements have a thin shadow added to them, making them look slightly out of focus and softer than expected. Fringing can manifest in various colors and many situations. As I'm writing this review, I can't notice it in the Microsoft Word window, where I'm using a dark gray background and white font color. At the same time, the other half of the screen is taken up by a standard white-background webpage, where fringing is very apparent, and text looks disappointingly soft. To find out more about fringing in general and see some great examples of WOLED and QD-OLED panel fringing issues, I recommend you check out an excellent article published by PC Monitors. This of course isn't a critique aimed at KTC. Every WOLED (and QD-OLED) panel suffers from some level of fringing; it's something you simply have to deal with if you decide to go down the OLED route. For gaming, video and similar types of usage, fringing isn't an issue you should be worried about. However, if you mostly work with text and graphics, especially on a professional level, this could (should!) be a reason to steer clear of OLED monitors altogether. They simply aren't a good choice for productivity and pose a substantial downgrade from higher-end LCD monitors in that regard.

The KTC OLED G27P6 doesn't have a traditional LED backlight unit. Individual pixels of an OLED panel are self-emitting, and that's where many benefits of such panels, such as infinite contrast, perfect blacks, absence of haloing, and superb response times, come from.

Like its peers, the KTC OLED G27P6 uses a fairly heavy matte screen coating. It does a very good job of reducing reflections and preserving OLED blacks even in bright conditions. With SDR brightness being the biggest challenge for all OLED monitors currently on the market, having a screen coating that manages to preserve it in difficult surroundings is hugely beneficial. To some, the coating of the KTC OLED G27P6 might seem too heavy, but I don't have a problem with it, because the picture isn't perceived as grainy or dirty from a normal sitting distance.

In case you skipped the previous page of this review, allow me to reiterate an important characteristic of the KTC OLED G27P6: this monitor offers no way of deactivating the Auto Brightness Limiter (ABL). If you can't get used to the fact that the brightness of the panel constantly (and visibly) changes depending on what's shown on the screen, then this will be a dealbreaker for you. Most other OLED monitors let us turn this feature off to get a constant level of brightness at the expense of maximum brightness, which gets locked to around 200 cd/m². For most users – myself included – that's an acceptable compromise. Future owners of the KTC OLED G27P6 simply don't have the luxury of compromising in such a way, as ABL is always on, and there's nothing you can do to deactivate it. I wouldn't call it aggressive, but normal users will easily spot it.

To test the picture quality of the KTC OLED G27P6, I've used a combination of the X-Rite i1Display Pro and DisplayCAL, a powerful software solution for display calibration and profiling that is completely free assuming you own a supported colorimeter.

Picture Quality at Factory Settings

Because there's no way to disable the Auto Brightness Limiter on the KTC OLED G27P6, I did what most OLED monitor owners would do. I applied the default Windows 11 dark theme and had nothing open other than DisplayCAL's own window.


The brightness is set to 40 in OSD by default, and that results in a measured picture brightness of 182.9 cd/m², with the default Windows 11 dark theme applied, and nothing other than DisplayCAL's window being displayed. My first batch of measurements showed a decent white point, sitting at 6,620 K, and a black level of 0, which is one of the key benefits of OLED panels. When displaying black color, pixels of an OLED panel simply turn off, so there's absolutely no light emitting from them. That's as black as you can possibly go, and also the reason why OLED panels have such attractive, deep, inky blacks. At factory settings, the average color accuracy of the KTC OLED G27P6 is reasonably acceptable (∆E 2.47), but the maximum deviation is very high (∆E 7.2). Certain shades of green and blue are the worst offenders. Gamma tracking is very good in the 0-70% range and then starts to harshly deviate. This insinuates that the monitor is prone to displaying very bright content darker than required by the input signal. I wasn't able to spot major gamma-related issues with my eyes; the curve looks worse than I would assume. ABL may be kicking in and confusing the X-Rite i1Display Pro at higher levels while measuring gamma.

To improve the factory settings by using settings available within the OSD, I first visited the Color > Color Temperature menu, switched it to User, and then, with the help of the colorimeter, manually adjusted the individual color channels to come closer to the 6,500 K white point. Only the blue channel needed to be lowered to 45, while leaving the red and green channels at their default values (50). As for the brightness (Display > Brightness in the OSD), I cannot name the single best value, as the brightness is dynamically controlled by ABL, so it changes depending on what's currently shown on the screen. If you crank it up to 100, you will get an actual brightness of over 250 cd/m² when displaying a 100% white picture, but when the picture is mostly dark, the bright peaks will go well over 450 cd/m² even in SDR, and that's bound to make your eyes hurt during nighttime. The best tip I can give is that you experiment with the brightness and find a value that works best for you. For me, setting it to 80 offered a balance I was happy with.



After adjusting the settings as described we see minor improvements in white balance and color accuracy, but there are no drastic changes to overall picture quality otherwise. The picture subjectively looks excellent – a combination of rich, contrasty colors and deep blacks, accompanied by superb responsiveness of the panel, results in a thrilling user experience. This is the experience I had with every other 27-inch 240 Hz OLED monitor on the market. The instant attractiveness of a gaming OLED panel is remarkable. For users mostly focused on gaming, the magic won't ever go away; only those who work with text and graphics will eventually realize that the sharpness of such visual elements isn't as good as it could be if there was no fringing present.


The monitor offers several color spaces and switching to them locks you out of adjusting anything in the Color menu. You can still adjust the brightness though. I tested the sRGB mode to check how KTC configured it. As expected, the color accuracy improved greatly – average ΔE dropped down to 1.07, and the maximum measured deviation was ΔE 2.37. However, the white balance missed the mark completely, measuring 6,091 K, which is much warmer than desired.


This is what the CIE diagram looks like. I measured 99.9% coverage of the sRGB and 94.8% coverage of the DCI-P3 color spaces. The gamut volume equals 148.6% for sRGB and 105.3% for DCI-P3 color spaces, respectively. The measured Adobe RGB coverage is 90.3%, with Adobe RGB gamut volume reaching 102.4%.


This is what the luminance and color uniformity of the KTC OLED G27P6 look like when measured at 25 different patches across the panel. Please click on the image to see it in high resolution and examine the data in greater detail. There's of course no backlight bleed anywhere on the screen because there's no traditional backlight that could cause it. The brightness uniformity is decent, although not spectacular. The bottom left corner of the panel is on average 12.49% dimmer than the center, as is the entire upper edge of the screen. Similar deviations can be spotted in color uniformity. The contrast stability is very good, staying well within 6.5% across the panel. For gaming, none of this will cause you any issues. It's an issue for color-critical work, but nobody should look to buy a 27-inch gaming OLED monitor for such purposes.

Picture Quality After Calibration

I calibrated the display using the X-Rite i1Display Pro colorimeter and the DisplayCAL software solution.

Here's what we get after calibrating the monitor.



OLED monitors are much harder to calibrate than LCD monitors, but we still see great improvements in color accuracy. The gamma tracking still isn't perfect, but it improved, too.

HDR Performance

Because of their technological characteristics, OLED monitors, including the KTC OLED G27P6, are a great choice for HDR gaming and content consumption. If you turn on HDR in Windows, the KTC OLED G27P6 automatically switches to HDR mode, sets the brightness to maximum, and locks you out of settings like contrast, gamma, hue, and saturation. There are actually two HDR modes to pick from: HDR Standard and HDR Cinema.

These two modes primarily differentiate in color temperature and resulting peak brightness (depending on the window size), although neither is set up ideally. For best results, I suggest setting the monitor to HDR Cinema mode and switching the color temperature to Warm. That helps with color temperature and RGB balance issues; the picture loses its unpleasant blueish tint. Depending on the amount of bright content on the screen, the monitor will reach brightness peaks of 900 cd/m² for 1% white window size. At 10% window size, you can expect around 660 cd/m², dropping down to 150 cd/m² for full-screen sustained brightness (100% white). At 10% window size, you can expect around 720 cd/m², dropping down to 192 cd/m² for full-screen sustained brightness (100% white). That's brighter than the Corsair Xeneon 27QHD240, which I reviewed a couple of weeks ago.

Viewing Angles

The viewing angles of the WOLED panel built into the KTC OLED G27P6 are excellent. There's no visible shift in colors from any sitting position or when changing positions.