Out of the box the C34F791 provided a vibrant image with good balance overall. Gamma and white point were both within comfortable range of their targets of ‘2.2’ and ‘6500K’, respectively. The gamma tracked at ‘2.1’, essentially making some shades slightly lighter than they would be at a gamma of ‘2.2’. However; this did little to upset the strong vibrancy of the monitor and actually helped alleviate some of the ‘black crush’ associated with this panel type, slightly improving visibility in dark areas. This worked well for the intended uses of this monitor, we feel, and there are other ‘Gamma’ settings available if users wish to use them. The images below show the factory calibration report included with our unit and the gamma curve using our ‘Test Settings’, respectively.







Gamma 'Test Settings'

There are also a few ‘Low Blue Light’ (LBL) settings included with the monitor. Our preferred option is simply setting ‘Color Tone’ to ‘Warm2’, as this was highly effective in reducing blue light output from the monitor without strongly impacting contrast. It also allows manual control of brightness. The mode that is specifically marketed, though, is ‘Eye Saver Mode’. This creates a much dimmer and warmer image, without manual control of brightness. It also purposefully restricts the static contrast of the monitor so that it is extremely weak, intended to reduce the range of light levels outputted by the monitor and hence reduce the amount of time spent by the eye compensating for such changes. We certainly found this mode comfortable, but we didn’t feel our eyes ‘needed saving’ from more conventional settings anyway. For users with particularly sensitive eyes this would certainly be worth experimenting with, at least for prolonged reading sessions or perhaps in the evening.





For our ‘Test Settings’ we simply lowered brightness. There was no need for manual colour channel adjustments on our unit, as the white point and overall balance was pleasing after reducing brightness. Note that individual units may vary, however. We also reduced the sharpness slightly to ‘44’ as we found things unnaturally sharp with a very slight red fringe to text using the default value of ‘60’. As with everything else, though, this is something that should be set according to personal preferences. We have also included the ‘Response Time’ setting, ‘FreeSync’ setting for the monitor and refresh rate used in Windows, just for reference. Any setting not mentioned here, including contrast, was left at default.





Brightness= 45 (according to preferences and lighting) Brightness= 45 (according to preferences and lighting) Sharpness= 44 (according to preferences) Response Time= Standard FreeSync= Ultimate Engine Refresh rate= 100Hz





We used a BasICColor SQUID 3 (X-Rite i1Display Pro) to measure the luminance of white and black using a range of settings. From these values, static contrast ratios were calculated. This data is presented in the following table, with black highlights indicating the highest white luminance, lowest black luminance and peak static contrast ratio recorded. Blue highlights in the table indicate the results under our ‘Test Settings’. Except for the changes already mentioned in the calibration section or this table, assume defaults were used.

The average contrast ratio with only brightness adjusted was 2533:1, excluding readings at ‘0% brightness’ where the black point measurement lacked sufficient accuracy. The highest static contrast ratio recorded was 2725:1, which comes quite close to the specified 3000:1. Regardless of this, perceived contrast was strong and there was a distinct ‘VA look’ to things with quite good inky-looking deep shades. Under our ‘Test Settings’ a contrast of 2371:1 was recorded, which is in-line with the other readings really and only slightly lower due to rounding of the black point. The lowest static contrast was recorded using ‘Eye Saver Mode’ (41:1), but as mentioned earlier this is intentional. The ‘Basic Color’ sRGB emulation setting yielded the highest white luminance (314 cd/m²) and provided strong contrast – contrary to many sRGB emulation modes which adversely affect contrast. The minimum white luminance recorded on this table was 68 cd/m², which is not quite as dim as the competing models we’ve recently reviewed. This provided a luminance adjustment range of 246 cd/m².

There is a ‘DynamicContrast’ setting as a separate ‘MagicBright’ preset on this monitor. This completely locks off manual control of various settings, including ‘Brightness’, ‘Contrast’, Sharpness’ and ‘Color’. It allows the backlight to dim or brighten based on the overall level of light or dark being displayed on the screen. As usual, the backlight is controlled as a single unit and therefore there is no ability to compensate for intricate mixes of light and dark. The backlight reacted rapidly to changes in overall light or dark in a given scene, but we preferred manual control of the backlight and indeed other settings on the monitor.





PWM (Pulse Width Modulation)

This monitor does not use PWM (Pulse Width Modulation) to regulate backlight brightness at any level. DC (Direct Current) modulation is instead used, meaning that the backlight is considered flicker-free. This will be welcomed by those sensitive to flickering or other side-effects from PWM usage.





Luminance uniformity