On LCD screens (as our hd2) white uses LESS power.
On AMOLED screens (omnia 7) white uses MORE power.
HD2's a white background is best for conserving and attaining maximum battery life.
http://www.scientificamerican.com/article.cfm?id=fact-or-fiction-black-is
marek1 said:
On LCD screens (as our hd2) white uses LESS power.
On AMOLED screens (omnia 7) white uses MORE power.
HD2's a white background is best for conserving and attaining maximum battery life.
http://www.scientificamerican.com/article.cfm?id=fact-or-fiction-black-is
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Thanks, this i checked just 2days before one day i kept backgroud light and dark which differs in battery backup of 2hours(more in white) , this i checked because while googling i came to know that dark colors accents best for battery ,so in that test this is a part, anyway i came to know the exact reason behind that . thanks
By switching your HD2 screen to completely white you would save about 3% of your battery. You can't change your HD2 screen to completely white as the live tiles cover about 2/3's of your screen. So by switching to a white background you would save only about 1% of your battery.
Too fast.....
mickfarr said:
By switching your HD2 screen to completely white you would save about 3% of your battery. You can't change your HD2 screen to completely white as the live tiles cover about 2/3's of your screen. So by switching to a white background you would save only about 1% of your battery.
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You're assuming different colours use the same amount of energy as black, just as most people assumed a black screen uses less than a white one. Tch Tch Tch.
Does anybody want to do a scientific comparison of the energy consumptions of differently coloured tiles on black and white screens respectively??
stepthehen said:
You're assuming different colours use the same amount of energy as black, just as most people assumed a black screen uses less than a white one. Tch Tch Tch.
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You're wrong in your assumption, you don't compare apples and oranges. I'm comparing two identical phones, the only difference is one is using a black background and the other is using a white background.
Also I said by switching your background from black to white, I didn't mention switch any themes or anything else.
did anybody catch the word "backlight" the screen its self, ie, what is displayed isnt really an issue, the backlight sits behind the LCD screen, much the same way as it does on a TV or a laptop, for that reason you may have noticed that it is impossible for an LCD screen to display a black screen, it cant because it has a light behind it and the mask from the LCD panel comes out gray or washed out black.
Anyhow, any difference in the power consumption will be either down to the brightness settings or how much activity is on the LCD screen. more changes would equal more power, black has a single consistant change white does not have any as such, but as pointed out, the tile page will always be covered in something and thus would never be completely white. there may well be a difference between different colours/black in terms of powerusage but compared to the VERY BRIGHT backlight it would be tiny amounts of difference
in short, turn the brightness down and save a meaningful amount of power. fiddle with the colours and you could probably count the number of min savd on your hands
Statement from the university of the bleeding obvious.
Related
I'm fed up with the flashy effects and background picture/pattern nonsense of the WM5 default blue theme. I'm looking for something minimalist, that doesn't hog as much resources. Any ideas where to look for something like that?
Most downloadable themes I've seen have colorful backgrounds and shaded menubars etc. I don't need that crap. All I need is a black background, thin, single-coloured menubars and windowframes, no animations, you get the idea.
i have a Palm Vx i can sell you cheap
No, no, you don't understand. I like the technical features of the Universal. I love having the great screen for watching movies or browsing the web with Opera, or the Wi-Fi or the 3G for on-the move connectivity. It's all good. But it makes my heart cry to see all this potential crippled by the resource hogging OS that's running on it.
i understood what you meant, this was a joke.
i love this device as well, for precisely the reasons you mention, but to tell the truth i don't believe a "light-weight" skin would improve performance all that much, if at all.
it certainly is sluggish, and i wish it ran faster, but even so it's better than carrying a phone, an ipod and a camera around in my bag...
I think that acctually we should have white background to save more power. Black colour on TFT screens is created by put max power to pixels. White colour dotn consume more power that is needed to light a fluorescent tube in the display which is turn on anyway. just my 0.02$
nabuhonodozor said:
I think that acctually we should have white background to save more power. Black colour on TFT screens is created by put max power to pixels. White colour dotn consume more power that is needed to light a fluorescent tube in the display which is turn on anyway. just my 0.02$
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Are you sure about that? Isn't a white pixel getting max. power?
I am sure. In LCD screens, when turn on (not in some king of power saving mode) fluorescent lamp is always glowing so to get shades and dark colour You ll actually have to "cover" light with LCD pixel. For LCD crystals to block the light they must be applied with maximum power. So if You have whole white screen theres no crystall blocking light and screen consumes energy only to light fluorescent lamp. If You have dark picture lcd display have to draw more energy not only to light fluorescent lamp but also to max out energy to all pixels to block the light.
Here is the classic black today skin that I use. Its only 2kb and is extremely minimalist. Hope this helps!
@nabuhonodozor
The exact inverse of what you said is correct.
Basically, in order to achieve the WHITE colour the Red, Green and Blue elements need to be lit consequently needing MORE power than would be required to achieve the Black colour which wouldn't require any colour elements to be lit.
Hope this helps.
Q.
Just came across this:
Some Android phones are now shipping with OLED displays, such as Nexus One, the Droid Incredible, and the Samsung Galaxy. Organic LED displays have separate pixel elements for each color channel (red, green, and blue), and each channel has a different efficiency.
Take, for example, the Nexus One. If powering only the red pixels at full intensity draws a current “i”, then powering all green pixels draws “1.5i”, and all blue pixels “2i”. (These ratios are derived from empirical measurements, and don’t hold in all cases.) Also, it’s worth noting that OLED displays don’t have backlights like LCD, meaning that darker colors draw less power.
...
Filtering to show only red pixels only requires 35% of the original baseline OLED panel current, on average. Adding back the baseline current, the best case overall is about 42% of the original system current, effectively doubling the battery life. Also, showing only red pixels doubles as an awesome night vision mode, perfect for astronomy.
If you’d like some other colors added back in, the amber and salmon filters can help, while still offering about 56% of the original system current. It’s also worth noting that the Nexus One OLED display uses a PenTile pixel layout, giving it twice as many directly-addressable green pixels as red and blue. Thus the Green-only filter results in the visually sharpest text.
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http://jsharkey.org/blog/2010/07/01/android-surfaceflinger-tricks-for-fun-and-profit/
I think it's a neat idea, it's a hardcore battery-saving trick and would surely make you look like a geek, but I could live with my screen being only red or green if I was going to write a text, read some rss feeds or basic text-only things like that.
Although I would be quite worried about shortening the life of the red AMOLED channel by doing this for a long time...
I saw that article on engadget today, i too would be very willing to go all red for that kinda current savings.
just read about this on androidandme, i would love to have this implemented for night viewing and what not.
I would think that you could also save quite a bit of battery power just by using white text on a black background for web pages and ebook reading instead of black on white.
malicious85 said:
just read about this on androidandme, i would love to have this implemented for night viewing and what not.
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I too would like this feature. Just switch the black with white text to black with red text.
Red text against a black background is supposedly easier for your eyes at night, too. I can't find a source to back that up, but i seem to recall that the longer wavelength keeps your eyes dilated, thus better able to see at night.
vincentm said:
I too would like this feature. Just switch the black with white text to black with red text.
Red text against a black background is supposedly easier for your eyes at night, too. I can't find a source to back that up, but i seem to recall that the longer wavelength keeps your eyes dilated, thus better able to see at night.
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^this. thats why spec ops have red flash lights. less strain on the eye + better vision
Very Interesting...would be a great feature
Real savings are much less since screen is not on all the time.
Sent from my Nexus One using XDA App
I hope some devs read about this.
Someone should forward this to Mister Cyanogen
I betcha his team could do something remarkable with this.
For some of the uses I'd like to use the OS for, this would have huge benefits.
I have also heard that the lifespan of the blue color in an amoled screen is significantly shorter than red and green, so maybe it could also be used to compensate this a little.
I really would love to see this included in a rom, let's hope some of the gurus here find it interesting too!
Cyanogen already added it yesterday in his mod http://github.com/cyanogen/android_development/commit/3d7046b51e7e08a66eb0958e7819b5961fee1484
eug89 said:
Cyanogen already added it yesterday in his mod http://github.com/cyanogen/android_development/commit/3d7046b51e7e08a66eb0958e7819b5961fee1484
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great! I was always reluctant to use cyanogenmod due to its (perceived) battery usage, now this could be gone
make it an option when ur battery is below 15%, terminator mode.
As seen by the NoLED app over in the dev section, and in a few other places on the net, people are finding that when they display a black image on their amoled/samoled screens in a dark room there is still light emitted by the display. it is not truly black
I would like to know why!
One thing i hear is about image compression and signal noise causing the pixels to not display #000000 black and instead a variant of black/grey causing the pixel to become lit.
This problem is not an issue during the day, i can't tell the difference when my screen is displaying black or off. but what it does effect is battery life.
If the screen isn't powering down its pixels then it is not saving anywhere near as much power as it could do
Also
How happy are you with your display?
I knew about the pentile problem before buying, however i am not dissatisfied with the display at all. Infact if i did not read up about it i would not have realised there was anything different with the screen.
Text is clear and sharp, images are vibrant, and colours seem true with no issue of pink problems like the desire
looool, look at any lcd screen(tv whatsoever) and you don't have true black, because the backlight is on. Only the best LED LCD screens in TV world have FULL LED backlight that can dim the leds from parts of the screen that are fully black in the processed image.
take care
yup, if you take apart your LCD watch, phone, laptop or monitor
you'll see 2 layers, first layer the LCD/TFT/AMOLED/SAMOLED/etc whatever new technology screen you can think of name it here.
then the bottom layer is pretty much like a light bulb/white led/ccfl or whatever you want to call it to light up the first portion of the screen.
most devices you can control the 2 separate pieces separately via "screen" and "back light"
you'll noticed that usually on software options what specifically lets you control both indedpendly.
Eh.. Yes But the SGS hade OLED screen. So it should be able to turn pixels completly off. My guess is that each led has some very small current applied to it possibly to speed up response off screen.
But it come close to true blacks..
EDIT
OLED screen has NO backlight... Each pixel is an tiny led...
Sent from my GT-I9000 using XDA App
thanks for the heads up, that's good to know
i've yet to take apart a new SGS to figure out how the AMOLED displays works
You guys need educating on displays lol
oled screens have no backlight, thus no backlight bleed.
That means that this is a software issue, unless the screen not powering down completely is intentional
Software issue and nothing more.
Open up the calculator, drag down the numpad, hide the 2 stripes (status bar and numpad drag bar) in the top and bottom of the screen, and tell me if you see any lighting.
There's absolutely nothing.
there is still light emitted. cover up the top and bottom bar with your hands, go into a completely dark room then look into the center of the screen.
There is a uniform glow, just like when looking at a black image in the gallery or browser
It's actually more noticeable if you look AWAY. The peripheral area of your retina will be able to pick up a very feeble amount of light. Feeble, sure, but it's there nonetheless.
seriously, guys?
XQC said:
seriously, guys?
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The problem is that the way it is supposed to work is that if you display black, the screen shouldn't use any energy at all but it is and people can see it and so is using precious battery charge.
The issue is... that apps like noled which were going to display a red dot on the screen to let people know if they had mail waiting or whatever wouldnt use much power at all because they were displaying mainly a black screen but it isnt actually black and still using light so still chews through the power..
hope that made sense.. but that is why people are interested in it..
Ok, I missed the battery part, sorry If so, it is indeed an annoyance...
I thought people were seriously complaining about image quality.
I have the Samsung wave and it uses the same screen technology and I can tell that it does not have true blacks pixels are still lit, I can easily tell that its on and totally off there is a very faint trace amount of light produced..
Since I first got this device and turned it on I have been impressed with the display. I am kind of partial to AMOLED diplays and am, thus, a bit biased. What surprised me was that it "appeared" sharper than the display on the Nexus One. Considering it is slightly larger and at the same resolution I just assumed that it wasn't using the PenTile arrangement - yet it appears that it does in fact use the same subpixel arrangement as the screen on the Nexus One. My point is... now I've forgotten my point. Basically that I am more than satisfied with this display.
As far as the black issue is concerned I have no idea. There must be some reason considering that was one of the supposed strengths of this technology (i.e. true blacks and lower power consumption).
El Mono
wait so why would you display an image if you want to save battery?
really
How many of you have measured how much power is being used up when the display is displaying a true black image(measured with multimeter, or other measuring device)
How many of you have made sure that the glow is not caused by a residual charge in the display?
How many of you know how much time it takes for the "glow" to leave an OLED panel when power is not being applied?
just some food for thought
The thing is, amoled screens were advertised as having true blacks and having the pixels off when displaying black. this is clearly not the case
It's not an issue with the technology. The screen doesn't have a back lighting panel, so i think it's more of a problem of what shade is default defined as "black" in the system, or something with any current running through the screen.
Well considering the screen doesn't turn off when displaying a 100% black bitmap image, its safe to say that the say that the pixels NEVER turn themselves off during use when displaying black
Could be the screen isn't calibrated properly, or they lied to us about the tech(wouldn't be the first time).
While its not "true black" it is defenently beyond what any backlit screentype can do regarding blacks.
Except perhaps for the retina display forged by god himself
But I agree that if Samsung states True black then it should be able to do that.
Sent from my GT-I9000 using XDA App
Because of the hight battery drainage from WP7, I was wondering what background screen is the best for our HD2 battery:
White or Black screen ?
Thank you everyone.
White would use less power but I don't think you'll notice the difference
radiance26 said:
Because of the hight battery drainage from WP7, I was wondering what background screen is the best for our HD2 battery:
White or Black screen ?
Thank you everyone.
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HaHa..Black easily wins. Takes more power to light up a white screen.
jawash22 said:
HaHa..Black easily wins. Takes more power to light up a white screen.
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Only on AMOLED screens
Nope
For LCD white is less power drain then black... but it not to much different
i unplgged my phone around 10 am this morning and have been messing around with it ever since, changing background, changing themes, texting, web, music, market, its now 7:51 pm, and its still has some charge to it, its asking for charge the little light is blinking. so think it black would use less battery, but i would really mattter since we are never at our home screen as much.
jawash22 said:
HaHa..Black easily wins. Takes more power to light up a white screen.
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LCD screens work by having a white light on all the time. They cannot display black colours, the only way it is possible is to close the tiny cell, to close that cell takes energy to keep it closed. If you look very very very very very closely you can see that the white light escapes around the cell. So when you look at the phone normally it black look grey because of the white light. Actualy its easier to see on your computers LCD screen.
Here's a picture of the little tubes hidden behind the screen:
http://asia.cnet.com/i/r/2009/tv/62055838/ledvlcd_2_440x281.jpg
Thank you everyone I will not regret to put the with background screen now
i just wondered how the battery consumption is on white compared to amoled screens? since i had a gs2 before i've been hesitating to choose white backgrounds to not to drain my battery.
I don't think colours matter on LCD screens, so black won't save any battery either
Exactly. Black colors will conserve your battery on AMOLED screens, but not LCD screens.
Sent from my Nexus 4 using xda premium
so there won't be any difference?i believe in daylight time it's more reasonable to choose lighter colors than darker to see the screen.
Simple answer: There is no affect on battery life. It will drain just as fast on white as it will on black.
Basic screen technology lesson incoming...
The image displayed on a regular LCD screen (aka most phones) will not affect your battery life. Only AMOLED screens (aka most Samsung phones) are affected by this phenomenon because the image is also the lightsource.
Battery life with LCD screens is affected by the backlight brightness. The backlight covers the whole back, is always white, and only shines through the LCD to allow you to see the image. Turn up the brightness, consume more power. Turn down the brightness, consume less power. Has nothing to do with the image on the screen.
Amoled screens do not shine through anything, the image they produce is also producing the light. That's why blacks use no power (off), and whites use max power (all on).
The end.
OLED looks OK but I never liked it on my S2 and the S3 looks the same TBH.
OLED looks green/bluish in tone. Whites are not as crisp as LED either.
Also OLED consumes MORE on White than LED on White at the same light output !