Results: Pixel Response, Input Lag, And Blur Reduction
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.
We had to do things a little differently for this review because our pattern generator only goes up to 60 Hz. So, we filmed a mouse movement that triggers the field pattern’s appearance. Since this is less precise than using the generator, we averaged five measurements. Here’s the screen draw result.
We were impressed to see the BenQ edge out Asus in this test. This is why a high-refresh monitor is so good for 3D gaming. There are blur reduction techniques discussed below that you can use to improve motion resolution, but it all starts with a fast panel like the XL2720Z.
Here are the lag results:
A new king of low input lag is crowned! Even a novice gamer like me can appreciate and benefit from this kind of performance. My aim is far more precise. My hit rate is higher. And motion is super-smooth with almost no loss of resolution.
Blur Reduction
BenQ puts a lot of effort into enhancing the gaming experience with its XL2720Z. In addition to the 144 Hz refresh rate, it employs a few extra features to minimize motion artifacts.
The principal one is a strobe backlight. You might associate this terminology with Nvidia's LightBoost, originally developed to improve image brightness with 3D Vision and minimize crosstalk. BenQ calls the feature Blur Reduction, though the fact that some folks like it more or less than LightBoost suggests the two implementations differ. In essence, though, the monitor's backlight turns on and off at a rate that matches its refresh rate. The net effect to the eye is smoother motion.
Of course there is a tradeoff: lower light output. When you activate Blur Reduction on the XL2720Z, brightness is reduced by almost 58 percent. Fortunately, there is a way to adjust this through a third party utility we obtained free from Blur Busters.
If your XL2720Z (or any Z-series BenQ monitor) has the latest firmware (v2.0), you can use this utility to control the persistence and strobe phase, affecting motion, brightness, and crosstalk. The utility is vastly superior to the on/off choice BenQ gives you.
The Persistence slider moves between greater light output and greater blur reduction. You can use the tests at Blur Busters to set this to your liking.
Crosstalk on an LCD manifests as ghosting or faint outlines behind moving objects. Adjusting this slider changes the timing of the backlight’s strobing action, putting it earlier or later in each refresh cycle. Again, check out Blur Buster’s tests to find your preference.
There are a number of the tests at blurbusters.com that demonstrate the effects of blur reduction. In most of them, the XL2720Z’s motion rendering is very smooth, particularly at high refresh rates, even with Blur Reduction turned off. When you increase the pixel-per-frame rate though, switching it on helps improve motion resolution. The most telling examples are the scrolling text tests. At 144 Hz, you can easily read rapidly-moving text. And with Blur Reduction turned on, there is no perceived loss of resolution.
