PC Magazine’s PJ Jacobowitz and Sascha Segan collaborated with DisplayMate’s Raymond Soneira to test color accuracy, contrast ratio and brightness on the Nexus One, iPhone, Droid and CLIQ smartphones (source: “Nexus One, iPhone and Droid: Which is Brightest?“). DisplayMate‘s tests were used along with a Konica Minolta CS-200 Chromameter. So here are the results:
- Color Accuracy: #1 Droid, #2 CLIQ
- Contrast: #1 Nexus One, #2 CLIQ, #3 Droid, #4 iPhone
- Brightness: #1 iPhone, #2 Droid, #3 Nexus One, #4 CLIQ
PC Magazine concludes:
So who has the best screen? We’d vote for the Motorola Droid. While the iPhone’s screen is brightest and the Nexus One’s colors pop, the Droid has the best balance of brightness and accurate colors on its 848 x 480 LCD panel.
Color Accuracy: Interestingly color accuracy was tied to the color gamut of the displays. The Droid had a color gamut of 98% NTSC. The iPhone was lowest at 63% NTSC. On the other hand the Nexus One had the highest at 141%. Similar to the Droid was 103% for the CLIQ. In my opinion color gamut by itself has little to do with color accuracy. To get accurate colors the colors need to be hardware or at least software calibrated to work with the OS and apps. If there was a smartphone display color calibration hardware tool (is there?) I would guess the Nexus One to have the most accurate colors since it has the most to choose from.
Update 2010.01.22 11PM: I turns out color gamut is related to color accuracy. Dr. Raymond Soneira, President of DisplayMate, corrected my thoughts on color accuracy. Specifically, based on the standard color gamut of sRGB/Rec. 709, if the display hardware has a much larger color gamut the colors will be over-saturated. The display should have a 100% of the sRGB/Rec. 709 color space for the most accurate colors. Based on information from Wikipedia, the ITU-R BT.709 (also known as sRGB/Rec. 709) has the following color space parameters:
- Red (x,y): 0.64, 0.33
- Green: 0.30, 0.60
- Blue: 0.15, 0.06
Contrast: There are three ways to improve contrast. One is to make blacks darker. Another is to increase the brightness. And the last is to do both. The Nexus One is certainly at an advantage since it is the only smartphone in the group to sport an OLED display. Black on an OLED display is almost completely black since it does not emit any light. LCDs, on the other hand, continue to pass through light from the backlight unit making blacks more darkish grays than really black. No contrast ratio numbers were shared but I would like to see the numbers both indoors (completely dark and typical office) as well as outdoors on a bright sunny day. The Droid passed through 0.26 cd/m2 of brightness when black while the CLIQ’s brightness was less at 0.21 cd/m2. The iPhone was dead last at 2.5 cd/m2, meaning that blacks were much less black compared to the other three.
Brightness: I don’t think brightness by itself is a measure of the quality of the screen but on a mobile device like these smartphones brightness does count for a lot more than say on desktop monitor. The reason being that you’ll need to be able to overpower the sun’s reflections outside. The iPhone had the brightest display at 444 cd/m2 when displaying white. The Droid’s spec was 391 cd/m2, Nexus One was 229 cd/m2 and the CLIQ came in last at 224 cd/m2. I would like to have seen what the brightness levels were for these smartphones with a typical screen instead of all white.
To make this type of test more exhaustive I would like to see the best smartphones using other mobile OSes included in the comparison: BlackBerry, webOS, Symbian and Windows Mobile. I look forward to a Round 2.