This is Part Ib to Display Showdown: Nexus One, part of the Display Showdown: Nexus One vs. iPhone 3GS, that looks at Color Temperature and Chromaticity, Color Gamut, Intensity Scale and Gamma. There seems to be more problems associated with the Nexus One display:
Color Temperature and Chromaticity: 8870Â° Kelvin
The color temperature for the Nexus One is 8870Â° Kelvin, which is bluer than the standard D6500 (6500Â° Kelvin). Although there are color temperature preferences in different parts of the world, D6500 is the color of daylight and is required for accurate color. As you may already know the blue OLED phosphor is the weakest among the primary colors used in OLED displays. In the PenTile Matrix 2×2 sub-pixel structure the red and blue phosphors are double the size of the green. This design was used to drive the blue phosphor less minimizing differential aging where the blue phosphor typically ages faster than the other two colors. Unfortunately the blue is still driven too hard resulting in a bluish display. To improve the overall color accuracy, minimize differential aging, and improve battery performance the blue needs to be driven even less.
The Nexus One has a much greater color gamut than the standard sRGB and results in over-saturated colors. It is commonly understood that a wider color gamut is generally better, but it is a misconception. Content is usually created with sRGB and until a wider color gamut becomes a standard wide color gamut displays will exhibit poor color accuracy. Wider color gamut displays do not show any colors that are not in the original images and result in color distortion. The actual color gamut chart (Figure 2) for the Nexus One can be seen at DisplayMate.
Intensity Scale and Gamma
The intensity scale on the Nexus One is too steep, irregular and non-standard, resulting in contrast and color distortions in images. One cause may be due to poor factory calibration and quality control. At some points in the irregular intensity scale the contrast is washed out and in other points the contrast is overblown. False contouring can result from these irregular variations, exacerbating the false contouring due to the limited 16-bit color depth. Hop on over to DisplayMate and look at Figure 3 for more detailed information.
The Nexus One’s OLED display certainly does pop and if that is your preference it is one of the most popping displays you will find on a smartphone. On the other hand if you are looking for a smartphone that produces accurate contrast and colors the Nexus One is not adequate.
WHATâ€™S UP NEXT
Next, Dr. Raymond Soneira and I will be adding more interesting results from the Measurements and Test Pattern Tests for the Nexus One:
- Part Ic: Brightness Decrease with Viewing Angle, Contrast Ratio Shift with Viewing Angle, Color Shift with Viewing Angle
- Part Id: RGB Display Power Consumption, OLED and LCD Spectra
For screen captures, more technical and in-depth explanations please visit DisplayMate.