The “PWM” Means Pulse Width Modulation And It Controls How Dim Your Screen Can Get
PWM dimming means Pulse Width Modulation dimming, but I understand that knowing what the word means in full doesn’t help at all. It’s a screen technology that is utilized to dim the brightness of a display.
Imagine you have a light bulb that takes a full second to hit its maximum brightness. When you want 100% of its light, all you have to do is switch it on, and in one second, the entire space is brightly lit. But what if you want only 50% of the bulb’s brightness, but all you have is that one switch? Well, what you can do in that case is to switch the light on and off repeatedly to prevent it from getting to its full brightness (forget about potentially breaking something like you might do in the real world). This is how PWM dimming works with display units.
However, just keep in mind that most phones only allow PWM dimming to kick in at the lower levels of brightness. So other dimming methods might be used above 50% brightness, for instance.
How Can PWM Dimming Have An Impact On Your Well-being?
“But Ayomide,” you say. “Wouldn’t a light flickering over and over like that eventually give you a headache, strain your eyes, or drive you mad?” Yeah, probably. Which is why the solution is to get a robot to flick the light on and off so many times in a second that the human eye can’t even catch the flickering that’s taking place. Instead, it’ll seem like the light is at a constant low brightness level with no flickering. This, is where the PWM number comes in.
A screen with a PWM dimming rate of 200Hz flickers 200 times each second in order to give you lower brightness on your phone’s screen. The thing is, while that sounds like a lot, your eyes might actually notice the flickering and that can lead to headaches and eye strain, and that sucks, especially at night when your screen is most likely to be at its dimmest.
This is why manufacturers (like Honor with the 200 series that launched today) are pumping up the numbers and getting your screen to flicker so many times in a second that it’s entirely imperceptible to the naked eye. With that, you won’t get the side effects like headaches, eye strain, or the urge to throw your phone through the wall. Screen sizes, resolutions, and refresh rates have reached a reasonable maximum, so quality-of-life features like these are a good place for OEMs to focus.
Here’s a fun trick you can try out: use another device to record your phone’s screen at a lower brightness, and you might catch the flickering on camera, especially if you’re recording an older phone.
Which Smartphones Right Now Have Notably High PWM Dimming Numbers?
Trying to save your eyes from getting fried when reading ebooks at the lowest brightness in the middle of the night? Here are some smartphones that you can rely on to take it easy on your eyeballs.
