Brightness And Contrast
To read about our monitor tests in-depth, please check out Display Testing Explained: How We Test Monitors and TVs. Brightness and Contrast testing is covered on page two.
Uncalibrated – Maximum Backlight Level
The X34 is a premium-priced gaming monitor so we've included other high-end displays in today's group. Acer's other two-curved screens are here, the Z35 and XR341CK. From Asus we have the PG279Q. BenQ is represented by the XR3501, the only screen here without adaptive-refresh. And ViewSonic brings in an Ultra HD model with its XG2700-4K, which we recently reviewed.
The X34 meets its claim of 300cd/m2 almost exactly. There's more than enough light output for anything a user might want to do.
The two AMVA panels walk away from the pack on black levels but the IPS-based X34 is the best of the rest. This result is aided by the fact that it has the lowest maximum output.
Max contrast is right in line with the other IPS screens in the group. After recording this number and realizing we'd have to lower the contrast slider to render full detail, we were a little worried what the calibrated result would be. Read on to see what we found.
Uncalibrated – Minimum Backlight Level
Acer sets the minimum output low as a design feature it calls Low Dimming. Low is right when you're talking about 16cd/m2. We'd have a hard time using the monitor this way but some users may prefer it. To reach 50cd/m2, set brightness to 11.
The super-dim backlight results in a black level even lower than the two AMVA screens here. It's not a fair comparison since the aforementioned displays have about double the contrast of their IPS counterparts.
The X34's contrast stays pretty consistent through its entire brightness range. The ideal candidate is Acer's own Z35, which renders around 50cd/m2 at the minimum setting with over 2600:1 contrast. That's some serious image depth.
After Calibration To 200cd/m2
The spread between the bottom four screens is fairly small and few users are likely to see a visual difference in calibrated black levels.
Thanks to well-engineered grayscale controls, we were able to maintain a calibrated contrast ratio over 1000:1, even though we reduced the contrast slider by over 20 percent. This is necessary not only to render full detail but to ensure white point accuracy at the 100-percent brightness level. Even if you don't change the RGB sliders, we strongly recommend lowering contrast to 44 to prevent clipping and fix the gamma tracking; more about that on the next page.
ANSI Contrast Ratio
Our X34 press sample exhibits excellent uniformity but the ANSI result takes a slight dip below 1000:1. This isn't a deal-breaker by any stretch and it closely matches the numbers recorded from the other IPS screens in the group. AMVA is still tops for contrast and despite the lower resolution of the top two displays (they're 2560x1080) we'd still lean towards them as our favorites for image quality.