This is Part IId of theÂ Display Showdown: Nexus One vs. iPhone 3GS series taking a closer look at the iPhone 3GSâ€™ Display Power Consumption and Display Spectra.
Display Power Consumption
Unlike an OLED where power is consumed only when it is emitting light, the backlight is always turned on in a mobile LCD. Power consumption is dependent only on the brightness setting. The average power consumed during standby mode when the display is black is used as the baseline. Luminous efficiency is luminance divided by power and is normalized to 1.0 for peak white.
- Black: 0.81 watts, 3 cd/mÂ², 0.007 relative luminous efficiency
- Peak Red: 0.81 watts, 84 cd/mÂ², 0.20
- Peak Green: 0.81 watts, 288 cd/mÂ², 0.67
- Peak Blue: 0.81 watts, 65 cd/mÂ², 0.15
- Peak White: 0.81 watts, 428 cd/mÂ², 1.00
The iPhone 3GS uses considerably more power compared to the Nexus One but also generates quite a bit more luminance. For instance, the iPhone 3GS’ peak green puts out 288 cd/mÂ² while on the Nexus One it is just 193 cd/mÂ². The Nexus One beats the iPhone 3GS being a power miser but doesn’t get the job done in bright environments.
The display spectra is the spectrum of the backlight filtered through the individual red, green, and blue sub-pixel filters within the panel. By usingÂ Konica Minoltaâ€™s CS-2000 Spectroradiometer, the LCD’s red, green, and blue spectra were measured: the iPhone 3GS display spectra is a filtered broadband spectrum but with a fairly narrow blue spectra.
You can find more technical and in-depth explanations atÂ DisplayMate.