Database Users

Night-vision screen mode

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.
Click to expand...
Click to collapse
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.
Click to expand...
Click to collapse
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.
Click to expand...
Click to collapse
^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
Click to expand...
Click to collapse
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.

Battery

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
Click to expand...
Click to collapse
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.
Click to expand...
Click to collapse
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.
Click to expand...
Click to collapse
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.

Screen contrast weird thing going on.

Hi
I just noticed something weird going on, the more black I have in the screen the brighter the whites get. Asif the more oleds are turned on its draining more power and making the other oleds loose overall power.
sent from I9100 using Omega

CONTRAST.
jje
Sent from my GT-I9100 using xda premium

To expand, the more black there is around the white, the more white the black seems in comparison, that is contrast.
And as the AMOLED pixel is its own light source the contract is already very high, as a black pixel is an off pixel not giving out any light.

veyka said:
To expand, the more black there is around the white, the more white the black seems in comparison, that is contrast.
And as the AMOLED pixel is its own light source the contract is already very high, as a black pixel is an off pixel not giving out any light.
Click to expand...
Click to collapse
Hence why having a black background saves power and also lessens the chance of screen burn on amoled displays.
Sent from the valley of the shadows....

For me it is the "Auto adjust screen power" on display settings menu.

RE
Yeah i got a bit different. always when i drag the statusbar the screen gets brighter or get flickering someone got this too?

blizzari said:
Yeah i got a bit different. always when i drag the statusbar the screen gets brighter or get flickering someone got this too?
Click to expand...
Click to collapse
Yeah exactly the notification menu dragging makes it really obvious.
sent from I9100 using Omega

goTouch said:
For me it is the "Auto adjust screen power" on display settings menu.
Click to expand...
Click to collapse
Yeah, definitely that. This function is on by default and limits the maximum power drain of the screen, so if there's a lot of white (or bright colors) on screen it will limit the overall brightness in order to save power.
I think it's very irritating and disabled this feature about 1 hour after buying the phone and never turned it back on.

Thanks guys. Auto screen power definitely the culprit. The screen is allot more uniform and "normal" now. Nicer to use.
sent from I9100 using Omega

[ONLY SAMOLED]Brighter pixels at top edge if screen

After a year of usage, through using the antutu test app for LCD I noticed that the pixels on top edge of the screen are brighter than the rest. It's probably because of the black notification bar.
Can other users with super amoled NS check this and see how their panel holded up? The best way to check it is with a plain gray or blue image.
Thanks
neXus S i9020T - AOSP+ - SG Kernel - 100/1320 MHz

I've the i9023 myself, but current (possibly future, too) OLED panels degrade unevenly. Whites and blues use the most power and lower the brightness after prolonged use more so than reds and blacks (with blacks effectively turning off the pixels and draining little to no power and don't effect brightness).
These kinds of effects are likely going to be more prevalent now that some years have passed since the first OLED displays have appeared. For comparison, LCDs use a backlight behind the screen which uses the same amount of power between white and black, though blacks look a little grey. As a result, there is even brightness fade.

screen battery consuption on white colour?

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 !