Brightness & 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
We were tempted to compare the S2417DG to a group of premium IPS screens, but with prices at least 50% higher, that didn’t make much sense. Instead, we rounded up TN-based panels that all sell for between $200-$300. The Dell costs a little more than the rest but that’s because of its G-Sync module. All the other panels employ FreeSync technology. The samples are ViewSonic’s XG2401, AOC’s G2460PF and G2770PF, Asus’ MG278Q, and Nixeus’ NX-VUE24A.
With the exception of the Nixeus, all the panels offer more light output than is necessary for any indoor environment. The NX-VUE24A does manage to win the black level contest by virtue of its lower backlight level.
The important chart is the last one where we see the S2417DG at a slight contrast disadvantage to the others. While 821.5:1 isn’t far below our 1000:1 preference, ViewSonic and AOC manage to top that threshold. Realistically though, significantly higher contrast is only going to come from a VA panel. TN and IPS are pretty much stuck at around 1000:1 regardless of price point and features.
Uncalibrated – Minimum Backlight Level
There are a couple of reasons we run a minimum backlight level test. First, we’d like to see output at around 50cd/m2. That is an ideal level for dark room use without having to worry about eye fatigue. Second, levels much below that mean that each click of the brightness control is a larger leap, and therefore it becomes difficult to set a precise brightness level. Third, we want to see consistent contrast throughout the backlight’s range. It’s been a while since we saw a monitor that had a problem with that, and the S2417DG checks that box as well. But it does go too low. You wouldn't be able to comfortably use a monitor that’s only outputting 29cd/m2. To set output at 50cd/m2, set brightness to 8.
After Calibration to 200cd/m2
The calibrated brightness, black level, and contrast charts show the effects of ULMB. Whenever a backlight strobe is in use, output drops. The S2417DG addresses this with a pulse width slider, but our results show the maximum (brightest) setting. You can turn up the brightness control to 100 and achieve a much more useful 150cd/m2, but contrast is still reduced by 18%. The good part is that in Normal and G-Sync mode, calibration has not reduced contrast by any significant amount. While not quite as high as the others, the Dell offers a decent image with good depth and a decent dynamic range.
ANSI Contrast Ratio
The S2417DG loses a bit of ground in the ANSI test, but intra-image contrast is still pretty good. ULMB reduces this number as well. Visually, you'd be hard-pressed to tell the difference between calibrated examples of any of the panel in this group. The ViewSonic would likely stand out in a side-by-side lineup, but the Dell acquits itself reasonably well nonetheless.