When Apple rolled out the iPhone 5, they announced that it had a full sRGB gamut, which the new iPad almost achieves and would be a substantial improvement over the 4 and 4S displays. The slight increase in screen resolution and size means we are looking at a new panel than the previous generations used as well, with the new panel being speced at 800:1 contrast ratio and 500 nits of brightness. I don’t have a 4S to test, but used my iPhone 4 that was bought on launch day and has been in use since then for comparison. Numbers were run using CalMAN 5 software, and a SpectraCal C6 colorimeter that was profiled from an i1Pro spectrometer. All readings are the average of three measurements from the C6, except for very dark readings where ten measurements were taken for more accuracy.
For comparing the minimum black and white levels in the iPhone 4 and 5, I set the brightness to the minimum level where I could get a reading from a black screen. At the minimum value I couldn’t get any reading, which indicates that it’s below the 0.001 threshhold that the C6 is capable of reading. Both phones had a minimum black level reading of 0.006 nits, but the iPhone 4 had a white level of 5.669 nits compared to the iPhone 5 and its reading of 8.303 nits. This gives us contrast ratios of 1008:1 for the iPhone 4 and 1313:1 for the iPhone 5. Both are ahead of the specified numbers, but the iPhone 5 is clearly better here.
At maximum brightness, the iPhone 4 has a maximum white output of 390 nits, and the iPhone 5 clearly trumps that with 562 nits. The backlight of the iPhone 4 could have become slightly dimmer over time, but using LEDs it really should not have faded much. Black levels for the phones are 0.355 for the iPhone 4 and 0.412 for the iPhone 5. This gives us contrast ratios of 1097:1 for the iPhone 4 and 1364:1 for the iPhone 5. Clearly contrast levels have been improved here, despite the move to a larger screen that sometimes can affect them.
Looking at the grayscale, the iPhone 4 puts out an average dE2000 of almost 10 across the spectrum. The grayscale has a very noticeab...