Backdrops & battery life

[falkeid]

Do the colors on backdrop effect the battery life? For example, would the black backdrop
consume less power than a white backdrop?

Thanks.

[psycho_maniac]

first post so correct me if im wrong. but white backround on the ipods use less then a black backround

[falkeid]

Interesting. Black is zero, white is 256 so I thought white would use more power on LCD.

Rockbox default and Ipod are both using white background so I think that might be
the reason.

I will use white background.

Thanks.

[safetydan]

The use of backlight dominates any current draw that different colors on the LCD might have. So basically use whatever background image/color you like, but keep the backlight usage to a minimum.

[falkeid]

Backlight uses more power when it is on, and less power if it is dim.

So, black background should use less power. This conflicts using white backdrop.
I don't get it.

[elborak]

Backlight power consumption doesn't change with color. Only with brightness and duty cycle.

[safetydan]

It's pretty simple. The color of the LCD has a very, very tiny effect on the amount of battery used. So tiny that it's not worth worrying about. So use whatever background color or image you want.

If you're concerned about preserving battery life, don't worry about the background color, worry about the use of the backlight. Keep that to a minimum.

Edit:

Ah now that Llorean has replied I understand where your confusion comes from. Read his post.

[Llorean]

Backlight is either On or Off, it is NOT different for every pixel.

If you have every pixel "Black" and you press a button that lights the backlight, it doesn't mean that the backlight doesn't turn on, it just means that you don't see it as much because there are black things between you and it.

Think of it like someone turning on a flashlight then holding up fingers to make shadow puppets: Whether they make the shadows or not, the flashlight is still putting out just as much light.

[falkeid]

OK, I got it thanks.