Results: Viewing Angle And Uniformity
AOC's E1659FWU looks similar to other TN screens we’ve photographed. Detail is greatly reduced as you move off-center, especially in the up or down direction. If you set this monitor up on a desktop, be sure to angle it towards you. If you’re using it on your lap, it’s pretty easy to maintain a centered perspective. If the E1659FWU were brighter, it would do a little better in this test.
The On-Lap 1502I demonstrates a significant improvement over its TN-based predecessor, the 2501M. IPS really is the way to go here. Side to side, there is only a little light falloff and no color shift. Top to bottom reveals some light falloff and a blue color shift. This panel is much better than the last On-Lap we reviewed, to be sure.
Screen Uniformity: Luminance
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.
These numbers aren't as bad as they look. We can’t see any significant hot spots on either screen. As expected, GeChic’s more expensive IPS panel is a little better than AOC’s TN one.
Here’s the white field measurement.
Both the On-Lap 1502I and the E1659FWU deliver excellent white field uniformity. They measure as good as or better than most desktop displays we’ve reviewed.
Screen Uniformity: Color
To measure color uniformity, we display an 80-percent white field and measure the Delta E error of the same nine points on the screen. Then we subtract the lowest value from the highest. A smaller number means a display is more uniform. Any value below three means that variation is invisible to the naked eye.
We don’t have color uniformity data for the On-Lap 2502M or AOC I2757FH. However, with Delta E variations of 1.46 and 1.99, both portables being reviewed today have no visible color error on a white field pattern.