High power usage with dark theme ? (Clear Black)

[MrD33P]

Q1. I am just confused whether the apps with dark themes use Clear Black display or just simple black ?

According to me I think clear black display turns off display pixels of screen where black is used.
If apps use clear black then why power usage is very high ??

I use Fiction Book Reader to read books with dark theme, and I hoped it uses clear black and power usage should be very low but surprisingly power usage by fiction book reader is very high. All you want from a book reader is low power usage in long uses.

Q2. so tell me whether it is clear black used in apps with dark themes ?
Q3. and how much power does it save ? 1% or 2% or more ? (I use dark theme in all apps, if available)

UPDATE : I have Lumia 730

 

[Harrie-S]

First of all Clear Black does not use power it is a film which decreases reflections.
See Nokia?s ClearBlack Display (CBD): technology explained | OLED-Info.

OLED displays need more power to show white/color then black due to the OLED technology. So a black back ground uses less power then a white background.

But not only the screen uses power but also the rest of the phone uses power so it is difficult to say how much it saves.
So if you want to know it I would suggest to test it for example using the Fiction book reader and compare the usage with a white and black background.
I would expect that you will find a difference if you reading plain text but is you read comic's (with color) I do not think there will be a big difference.

 

[MrD33P]

I read plain text !!

Okay ... so which color consumes more power in Oled display Grey or White ?
Could you please sort power consumption in grey black and white ?

 

[Slovenix]

I read plain text !!

Okay ... so which color consumes more power in Oled display Grey or White ?
Could you please sort power consumption in grey black and white ?

White consumes more energy on Oled, while Black consumes more on IPS

 

[Harrie-S]

I read plain text !!

Okay ... so which color consumes more power in Oled display Grey or White ?
Could you please sort power consumption in grey black and white ?

As above OP already said white the most and back the least and grey somewhere in between.
But don't expect miracles and if you read a lot I would suggest an dedicated E-reader with an E-ink display because this display type uses really a fraction of the power compared with an LCD or OLED display.

 

[MrD33P]

No I am not a regular reader... I just hope to read sometimes when I travel and still want to save power .. see thats important when you travel :/

 

[xandros9]

White consumes more energy on Oled, while Black consumes more on IPS

what's being displayed on an LCD doesn't make a difference. Black, white, the backlight functions independent of whats on the screen unlike OLED.

 

[Slovenix]

what's being displayed on an LCD doesn't make a difference. Black, white, the backlight functions independent of whats on the screen unlike OLED.

I just remember that from the article about displays. After checking again I see that it doesn't apply for the IPS version. Actually still uses less when displaying black ~0.1%