Response Time And Final Words
In our last roundup, many of you requested some sort of a response time benchmark. It's extremely difficult to measure this aspect of LCD performance, though it's not impossible. All three of our 22" displays are TN-based, which stands for twisted nematic. TN displays contain liquid crystal cells that realign in order to allow light to pass through, depending on whether an electrical field is applied or not. A pair of polarizers filter the light, causing it to pass through as transparent or more/less opaque, determined by the voltage used.
The problem with benchmarking is that you need to measure the physical time it takes for this to occur. That's impossible with a normal camera or with the naked eye because it occurs within milliseconds. However, we can measure this with an inexpensive high-speed camera by shooting 1000 FPS and recording the time it takes for a completely black screen to turn to white. This captures the amount of time it takes for the TN-effect to switch.
|Full Black to White Response Time||16 ms||17 ms||18 ms|
Our response times represent a worst-case scenario because they assess a leap from black to white. In the real-world, your monitor is more likely to change brightness from one shade of grey to another. This occurs much faster than a full black to white conversion because you're only subjecting the cells to a partial twist. Manufacturers often supply response times that reflect grey-to-grey transitions, which is why our testing methodology is different, and indeed more taxing.
Obviously, long response times can be a major problem if you're gaming. You need your monitor to display scenes as fast as possible so that you have a bigger window in which to react. Ideally, you want response times less than 10 ms because they affect the input lag (the time you send a signal to the time it's displayed). We're still trying to figure out how to measure that particular attribute, but we should have something figured out in time for our next roundup. Here's a hint: we followed your recommendations and tracked down a handful of IPS-based screens.
In the meantime, we're going to go so far as to recommend steering clear of these screens and looking at 23" TN-based displays, if you insist on going the budget-oriented route. Compared to the last batch of LCDs we reviewed, two of which come from the same companies, they boast superior color and larger contrast ratios. According to our results, this trio of 22" LCDs don't offer many redeeming qualities in either discipline.
What monitors do you want to see us review next? Tell us below in our comment section and follow us on Twitter for a heads up on our other upcoming projects! Thanks again to Best Buy for helping us put together this roundup.