Picture Quality

The INNOCN 27C1U features a 10-bit IPS panel capable of displaying 1.07 billion colors. The panel is in fact 8-bit, but uses Frame Rate Control (FRC), a method of temporal dithering, to create the perception of a 10-bit panel with 1,024 individual shades of RGB color. Unless you're a creative professional with an established end-to-end 10-bit color workflow, you shouldn't lose any sleep over the 8-bit+FRC nature of this monitor. The screen uses a White-LED (W-LED) backlight unit. It's controlled by direct current (DC), which makes it flicker-free at any given brightness level.

The screen coating on the INNOCN 27C1U is light anti-glare (AG). The screen is resistant to reflecting its surroundings even when used in a room with a lot of natural or artificial light, and the picture isn't perceived as grainy or dirty from a normal sitting distance, which can be the case with heavier AG coatings. The maximum specified brightness of the panel is 400 cd/m², accompanied by a static contrast ratio of 1,000:1, which is standard for IPS panels.

To test the picture quality of the INNOCN 27C1U, I've used a combination of the X-Rite i1Display Pro and Datacolor Spyder5ELITE+ colorimeters, and DisplayCAL, a powerful software solution for display calibration and profiling, which is completely free to use if you own a supported colorimeter.

Picture Quality at Factory Settings

The picture quality of the INNOCN 27C1U at its factory defaults was tested right after plugging it in and allowing it to warm up for about an hour. At the factory settings, I measured a high brightness of 400.69 cd/m², with the color temperature sitting at 6.945 K, which isn't very close to the desired value of 6.500 K. The contrast was 993:1, which is above-average for an IPS panel, and the gamma was 2.41. All this combined resulted in a very punchy, contrasting image that looked appealing but didn't seem to particularly bother with naturality and accuracy. This was confirmed after performing a color accuracy measurement, where the colors turned out to be all over the place. The average ΔE was 3.67, but with a bunch of color tones deviating above ΔE 5 and reaching up to ΔE 8.22. Take a look at the following chart.



In terms of sharpness, the picture looks superb thanks to the high pixel density achieved by a 27-inch panel with 4K native resolution. Windows 11 recommends setting the UI scaling to 150%. If you keep the size of the Windows interface (icons, text, apps, and other items) at 100%, every element of the UI will be too small to be usable. As a minimum, the scale level should be set to 125%, but I generally agree with Microsoft's guidelines—150% results in the best overall user experience. One thing you should be aware of, though, is that scaling of the interface actually reduces the screen's available real estate. A scaling level of 150% at 4K resolution results in exactly the same amount of real estate on screen as with a 1440p display set to 100% scaling—it is the recommended default value. However, thanks to higher pixel density since the screen quite literally contains more pixels, a 4K panel will still be noticeably sharper regardless of the scale level. If you're after more screen real estate than you can get from a 1440p monitor, you should set the scale level to 125%.

A quick way to improve color accuracy is to set the monitor to sRGB Mode. By doing so, you'll be locked out of adjusting the color temperature and gamma, but the average ΔE will drop to 1.7, with the highest deviation not surpassing ΔE 3.19 on a certain shade of gray, which is a massive improvement over the factory settings. Here's what that looks like.



This also improves the white balance (6,662 K) and contrast ratio (1,038:1), although the gamma remains somewhat problematic; measuring 2.39 A, it means the picture will be darker than intended. Some users might see it as punchier, but a high gamma can and will result in crushed shadow detail, which is hardly ideal. Below is the measured gamma curve at factory settings, just so you can see what we're dealing with here.



Unfortunately, even though the INNOCN 27C1U offers a total of eight different gamma settings (1.6, 1.8, 2.0, 2.2, 2.4, 2.6, 2.8, and S.curve), I wasn't able to find a single setting that would result in an accurate 2.2 gamma value. The closest I was able to get to it was by switching the monitor to Uniformity Mode in the Professional menu and then manually adjusting the color temperature and brightness to get those parameters in line with what we wanted. On my sample of the INNOCN 27C1U this was achieved by setting the color temperature to user mode (Professional > C.T settings > User C.T1 > On) and then lowering the blue channel gain to 47 while leaving the red and green channels at their default values (50). The only remaining thing was to set the brightness (Picture Settings > Brightness) to 84. That resulted in a measured brightness of 249.07 cd/m², white point of 6.426 K, and gamma of 2.11. This is what the measured gamma curve looks like with the aforementioned adjusted settings.



Let's compare the results before and after adjusting the settings of the monitor. Let me remind you that we still didn't calibrate the monitor; all changes to its picture quality were done through the OSD.


While the gamma curve, brightness, and white balance look much better with my adjusted settings, there were no improvements in measured color accuracy. For that, we'll have to resort to a full hardware calibration of the INNOCN 27C1U and hope for the best. If you don't have a way of calibrating your monitor, you basically have to choose between improving its gamma by using Uniformity Mode along with my adjusted settings or color accuracy, which improves after setting it to sRGB Mode.


The measured gamut volume of the panel is 151.3% for the sRGB and 107.2% for the DCI-P3 color space. The actual gamut coverage is 99.7% for the sRGB and 92.6% for the DCI-P3 color space with my adjusted settings.


This is what the luminance and color uniformity of the INNOCN 27C1U 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. As you can see, backlight uniformity is very good, with no parts of the panel exhibiting any oscillations in backlight uniformity to the naked eye. When examined across various brightness levels, brightness uniformity averages to +5.07% on the most problematic part of the panel, which is the bottom-left corner, so it passes the nominal tolerance defined by the ISO 14861:2015 evaluation criteria.

Color uniformity is excellent, with an average ΔE of 2.14 or lower across the panel. My colorimeter picked up fairly high contrast deviations in the upper corners of the panel, but if it wasn't for the instrument readings, I'd probably never spot them with the naked eye.

Picture Quality After Calibration

I calibrated the display by using the X-Rite i1Display Pro colorimeter and DisplayCAL software solution. Initial profiling and calibration were done with the luminance target set to 250 cd/m², which presents a happy medium for comfortable combined daytime and nighttime usage. The calibration was conducted with the adjusted settings listed above.

Here's what we get after calibrating the INNOCN 27C1U.



After a proper hardware calibration, the INNOCN 27C1U becomes an entirely different beast. Suddenly, all of its issues are gone. The gamma now measures very close to our desired value of 2.2, and the color accuracy, well, just look at the chart. The average ΔE dropped from ΔE 3.24 to ΔE 0.4, and the maximum ΔE went from 8.39 to 1.58. That's an impressive improvement in color accuracy, one that makes this monitor a viable choice for color-critical work. We're talking about the same monitor that wasn't appropriate for anything even remotely demanding in terms of color reproduction before calibration.

Backlight Uniformity

To give you an idea of the backlight's uniformity, I set the brightness of the monitor to 250 cd/m² before taking a photo of the panel in a completely dark room. I did my best to find a combination of the ISO value and shutter speed that would capture the screen in a way that has it look as close to what my eyes were seeing in real life.



Some backlight bleed can be spotted near the bottom-left and right corners of the panel. It isn't noticeable in real life, even when watching dark movies or playing dimly lit games.

Viewing Angles

This being an IPS panel, the viewing angles are great. There's no visible shift in colors when you change your sitting position. You'll have a lot of freedom to move your head any way you like. I didn't notice any noteworthy vignetting around the edges of the screen when viewed from a normal sitting distance.