Results: Viewing Angle And Uniformity
Aside from GeChic's On-Lap 2501M, this is the only TN monitor we’ve tested this year. Off-axis viewing is the weak point of any non-IPS or PLS screen. For a high-refresh rate display like the VG248QE though, TN is the best choice for stability and fast screen draw performance.
Side to side, the image quality is pretty solid. There is a little discoloration in the brighter signal areas, but blacks remain stable and you can still tell the darkest bars apart. Top to bottom is another story. Viewed from 45 degrees below the screen center, the image is almost completely wiped out. From 45 degrees above, the bars are very light, though still defined. When we shoot these photos, we set our camera to manual exposure so each shot is taken with the same aperture and shutter speed. The side to side performance is exceptional for a TN screen. The top to bottom is fairly typical.
To measure screen uniformity, zero percent and 100 percent full-field patterns are used, and nine points are sampled. In a change from previous reviews, we’re now comparing the results to other monitors we’ve measured. First, we establish a baseline measurement at the center of each screen. Then the surrounding eight points are measured and their values expressed as a percentage of the baseline, either above or below. This number gets averaged. It is important to remember that we only test the review sample each vendor submits. Other examples of the same monitor can measure differently in this metric.
First up is black field uniformity:
Out of the 12 monitors we’ve reviewed this year, exactly half are above 10 percent and the other half are below. At 7.98, the Asus is comfortably in the better-performing segment. You shouldn't see any bright or dark spots in a black field.
Here’s the white field measurement:
Looking at the 100-percent white field, there's a slight hotspot in the center of the screen and a slight dark area in the upper-left. These are admittedly pretty minor, and don't impact the quality of content.
Screen Uniformity: Color
Starting with our review of the AOC Q2963PM, we added a new uniformity test to our benchmark suite: color. The above measurements only address luminance. Now we’re measuring the white balance variation in an 80-percent white field pattern. The results are expressed as a variation in Delta E, in other words, the difference between the highest and lowest value.
Since this metric is so new, we only have results for the last three monitors we reviewed. With a Delta E variation of only .29, the VG248QE performs extremely well. There is no visible variation in color at any point on the screen.