Reduce white point


GreyOS

macrumors 68040
Apr 12, 2012
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Yes, my understanding is it changes the colour not the backlight, and my understanding is only a reduction in the latter would improve battery life.
 

perfect_

Suspended
Feb 8, 2016
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I'm pretty sure it has no effect on the battery or backlight. It just changes how the display looks.
- Adjust full brightness.
- Turn On Reduce White Point
- Turn Off Reduce White Point

Do this steps over and over again. Until u see the difference. Im pretty sure it has effect on the battery. Because brightness or screen light or pixel white colour or whatever reducing and this means lcd spends a little less energy.
 
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GreyOS

macrumors 68040
Apr 12, 2012
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How about go to a white screen and then go to a black screen
you see the difference?

well the backlight is still the same strength, using the same power
 

Paddle1

macrumors 68040
May 1, 2013
3,403
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- Adjust full brightness.
- Turn On Reduce White Point
- Turn Off Reduce White Point

Do this steps over and over again. Until u see the difference. Im pretty sure it has effect on the battery. Because brightness or screen light or pixel white colour or whatever reducing and this means lcd spends a little less energy.
What GreyOS said. That toggle doesn't change the brightness it just makes lighter areas appear darker. Just like a black screen, showing a darker image uses the same amount of power on an LCD display. Changing the brightness alone would not reduce the "white point".
 

perfect_

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Feb 8, 2016
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How about go to a white screen and then go to a black screen
you see the difference?

well the backlight is still the same strength, using the same power
No u are totally wrong. Lcd uses different energy these scenarios. Black screen uses less energy than White screen. And these feature has a 'Reduce White Point' name.
 

Paddle1

macrumors 68040
May 1, 2013
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No u are totally wrong. Lcd uses different energy these scenarios. Black screen uses less energy than White screen. And these feature has a 'Reduce White Point' name.
That's incorrect. LCD displays don't use less power when displaying black, LED displays do.
 

GreyOS

macrumors 68040
Apr 12, 2012
3,265
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That's incorrect. LCD displays don't use less power when displaying black, LED displays do.
edit: SORRY quoted the wrong person, wasn't paying attention

agree with you, perfect_has it wrong
[doublepost=1460578587][/doublepost]
No u are totally wrong. Lcd uses different energy these scenarios. Black screen uses less energy than White screen. And these feature has a 'Reduce White Point' name.
Reduce White Point is an accessibility feature and doesn't have anything to do with energy consumption
 

perfect_

Suspended
Feb 8, 2016
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That's incorrect. LCD displays don't use less power when displaying black, LED displays do.
We are reducing pixels white points. We are doing it pixel level with/or reducing screen brightness too with Reduce White Point. Maybe engineers added, reduce brightness, codes too in this feature like low power mode(it decreasing screen brightness too like reduce white point) If its incorrect then enlight us. I still believe what i see.

If i hold the 5W light to ur eyes. U should say this.
- Whats that.
(Turn on Reduce White Point)

If i hold the 80W light to ur eyes. U should say this.
- ~>|>?\•~^*{
(Turn off Reduce White Point)

Thats what im talking about and thats what i see. Reduce white point decreasing screen light. And low light means low energy.
 
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Paddle1

macrumors 68040
May 1, 2013
3,403
1,140
We are reducing pixels white points. We are doing it pixel level with/or reducing screen brightness too with Reduce White Point. Maybe engineers added, reduce brightness, codes too in this feature. If its incorrect then enlight us. I still believe what i see.

If i hold the 5W light to ur eyes. U should say this.
- Whats that.
(Turn on Reduce White Point)

If i hold the 80W light to ur eyes. U should say this.
- ~>|>?\•~^*{
(Turn off Reduce White Point)

Thats what im talking about and thats what i see. Reduce white point decreasing screen light. And low light means low energy.
Doing that would darken the whole screen, not just the white parts.

"The major benefits from OLED type displays comes from the high level of control that can be exerted over each pixel. Pixels can be switched completely off, allowing for deep blacks and a high contrast ratio. Being able to dim and turn off individual pixels also saves on power. The lack of other layers on top of the LEDs means that the maximum amount of light reaches the display surface, resulting in brighter images with better viewing angles."

From: http://www.androidauthority.com/amoled-vs-lcd-differences-572859/

You can't dim only the white areas by turning down the brightness. Changing the brightness isn't enough to change the contrast.
 

Paddle1

macrumors 68040
May 1, 2013
3,403
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Then reduce the brightness of the screen or just change the colors?
It does not appear to be brightness, from the other thread:
No, because that poster is incorrect. It doesn't dim the display.

It dims the white parts but leaves the colors and the dark parts of the screen alone. If you dim the display it darkens all of those things too.
Partially correct. Reducing the white point reduces the maximum values of a pixel. So if a pixel could have a range of 0-255 for each of the three colors, where 255 on all three produces white, then reducing it might make the maximum 230.

When this is applied, it impacts the brighter end proportionally more than the darker end, but it still does affect the entire spectrum, except for black or very very near it.

This differs from reducing the brightness as that reduces the LED backlighting. Reducing white point should be used secondary to reducing the LED brightness because it effectively reduces contrast.

It can help in dark situations, although inverting colors is still much easier on the eyes.
Read the thread here: http://forums.macrumors.com/threads/reduce-white-point.1717661/ if you want more information.
 
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abrahamr1991

macrumors newbie
Original poster
Apr 4, 2016
20
1
But if it dims the white parts and a pixel could have a range of 0-230, it would be reducing the brightness, no?
 

GreyOS

macrumors 68040
Apr 12, 2012
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But if it dims the white parts and a pixel could have a range of 0-230, it would be reducing the brightness, no?
There's a bit of a terminology issue here.

The Brightness setting on iOS controls the backlight. On a TV you'll often see a different setting for brightness and backlight.

Reducing white point is reducing brightness (in TV terminology) and doesn't save battery on iPhone screens; only reducing backlight does. And that's controlled by the Brightness setting. Confused? Lol
 

abrahamr1991

macrumors newbie
Original poster
Apr 4, 2016
20
1
There's a bit of a terminology issue here.

The Brightness setting on iOS controls the backlight. On a TV you'll often see a different setting for brightness and backlight.

Reducing white point is reducing brightness (in TV terminology) and doesn't save battery on iPhone screens; only reducing backlight does.
But it reduces brughtness, save more batery, no?
 

GreyOS

macrumors 68040
Apr 12, 2012
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1,550
But it reduces brughtness, save more batery, no?
No, as many people have stated over and over.

Let me use purely iOS terminology so as not to confuse matters.

1. Lowering brightness in iOS saves battery.
2. Reducing white point does not lower brightness.
3. Reducing white point changes the colour of pixels.
4. Changing the colour of pixels does not save battery on iPhone screens.

Got it?
 

abrahamr1991

macrumors newbie
Original poster
Apr 4, 2016
20
1
No, as many people have stated over and over.

Let me use purely iOS terminology so as not to confuse matters.

1. Lowering brightness in iOS saves battery.
2. Reducing white point does not reduce brightness.
3. Reducing white point changes the colour of pixels.
4. Changing the colour of pixels does not save battery on iPhone screens.

Got it?
I think it has become clear to me already hehe. Thank you very much
 
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