3 ms·
Making your screen all black saves energy. For many monitors this is not true. For a screen where the resting state of the LCD pixels are open displaying black
by onion2k 5y ago
Making your screen all black saves energy.
For many monitors this is not true. For a screen where the resting state of the LCD pixels are open displaying black means the monitor has to switch the diffuser to closed in order to block the light, which uses more energy than displaying white. There are lots of different LCD technologies which affect whether black or white is more efficient. For CRT screens black is always better.
https://www.scientificamerican.com/article/fact-or-fiction-black-is/ https://www.scientificamerican.com/article/fact-or-fiction-b...
- stavros 5y agoMy second screen (an LG) turns the backlight off whenever it's all black. My Dell monitors don't do the same, and it's a shame. It's always on but effectively off all the time as it usually is all-black, and thus there's no backlight.
- vbphprubyjsgo 5y ago> My second screen (an LG) turns the backlight off whenever it's all black. Did you test that setting every pixel black actually triggers this? Most OS just shut the monitor after inactivity (by ceasing to output video signal, or something like that).
- stavros 5y agoYes, it happens within seconds. It's not VESA blanking.
- vbphprubyjsgo 5y agoThat's a huge misfeature, then. Is it a computer monitor? Ahh maybe you are referring to dynamic contrast (which is still a misfeature).
- stavros 5y agoIt's a computer monitor, yes. I don't know about a misfeature, I love it. What's dynamic contrast?
- vbphprubyjsgo 5y agoI have never seen a monitor that turns off with a black screen (aside from dynamic contrast mode). What happens when the screen needs to turn back on? Does it freeze for 1-3 seconds? > What's dynamic contrast? Shutting certain backlights to raise the contrast between the dark side of the screen and the lit side. It has various undesireable side effects such as the darkening and lightening giant areas unexpectedly. They often try to make the transition gradual which just makes the screen even less real-time.
- stavros 5y ago> What happens when the screen needs to turn back on? Does it freeze for 1-3 seconds? No, it takes around 200ms for it to turn back on. > Shutting certain backlights to raise the contrast between the dark side of the screen and the lit side. Ah, no, there are no sections in this one, the whole backlight turns off and on.
- simooooo 5y ago
- mathrall 5y agoGreat read, it would definitely help us on the long run.
- vbphprubyjsgo 5y agoAnd the backlight (presumably 99% of power usage) is on no matter what you do with your pixels.