Display Showdown Part IId: iPhone 3GS

This is Part IId of the Display Showdown: Nexus One vs. iPhone 3GS series taking a closer look at the iPhone 3GS’ 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/m², 0.007 relative luminous efficiency
  • Peak Red: 0.81 watts, 84 cd/m², 0.20
  • Peak Green: 0.81 watts, 288 cd/m², 0.67
  • Peak Blue: 0.81 watts, 65 cd/m², 0.15
  • Peak White: 0.81 watts, 428 cd/m², 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/m² while on the Nexus One it is just 193 cd/m². The Nexus One beats the iPhone 3GS being a power miser but doesn’t get the job done in bright environments.

Display Spectra

The display spectra is the spectrum of the backlight filtered through the individual red, green, and blue sub-pixel filters within the panel. By using Konica Minolta’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 at DisplayMate.