Results: Pixel Response And Input Lag
To perform these tests, we use a high-speed camera that shoots at 1000 frames per second. Analyzing the video frame-by-frame allows us to observe the exact time it takes to go from a zero-percent signal to a 100% white field.
The pattern generator is placed at the base of the monitor so our camera can capture the precise moment its front-panel LED lights up, indicating that a video signal is being received by the monitor. With this camera placement, we can easily see how long it takes to fully display a pattern after pressing the button on the generator’s remote. This testing methodology allows for accurate and repeatable results when comparing panels.
Here’s a shot of our test setup. Click on the photo to enlarge.
The brighter section of the camera’s screen is what actually appears in the video. You can see the lights of the pattern generator in the bottom of the viewfinder. We flash the pattern on and off five times and average the results.
The screen draw time beats any IPS screen we’ve tested. Superior response is half the reason gamers still favor TN panels. AOC's G2460PQU is the only 144 Hz display in our comparison group, hence its much lower result.
Given the bandwidth requirements for Ultra HD, we are pleasantly surprised by the input lag results. AOC is on top again, exactly where you'd expect to find a 144 Hz screen. But for a 4K display to exhibit just 3 ms more lag than an FHD monitor is impressive. We expect gamers to be attracted to Asus' PB287Q based on its price alone, so the added bonus of low input lag is icing on the cake.