Results: Display Measurements
The first screen measurements we take are brightness because it’s important to know what your screen is capable of. The rest of our display measurements, along with our battery testing, is done with the screen set to a standardized light output of 200 nits in order to make device comparisons possible. We record the luminance output of each device using a full white pattern, with the device’s brightness slider set to both minimum and maximum values.
Nexus 5 achieves middle-of-the-road brightness at around 400 nits. While it is marginally brighter than the LG G2 and only 5% brighter than the HTC One, it nonetheless seems to sit at the darker end of the scale. Still, it's perfectly readable in daylight.
As an anecdotal aside, the Nexus 5 is often reported as being too bright, and modders have even released kernel add-ons that knock down the brightness of the backlight by about 20%. We tend to concur with the anecdotal feel rather than our measurement, but that may have more to do with the glossy glass and warmth of the panel’s colors.
Because the Nexus 5 has quite a low minimum reading, it should actually provide quite a lot of contrast, though not as much as devices like Tegra Note whose display reaches 420 nits easily.
To be sure of the contrast ratio, we had to calibrate the brightness slider to within one percent of our target 200 nits (which by the by was not much fun with sausage fingers; I’ll by opting for a stylus next time). We also checked the calibrated black level, or the luminance output of a full black pattern when full white has been standardized.
Now onto contrast ratio, or white pattern versus black.
As predicted, Nexus 5 has pretty reasonable contrast. It is on the lower end of the scale, yet it seems fine and nothing is a struggle to read or take in proper detail, even held at arm's length.
Color temperature is a measurement in Kelvin which is used to describe how warm or cool a given display is. These are colors derived from the CCT or correlated color temperature. All of the displays tested are in the cool range (basically any temperature above 4000 Kelvin), but the following chart should give some indication of how they tend toward one end or another of the CCT scale.
The iPhone 5s, LG G2, and particularly the Nexus 4 all sit at the upper end of the cool spectrum, with their whites tending toward a blue hue. Colors get warmer from the HTC One down to the Google Nexus 5, to the point where the Nexus 5 starts to remind us more lot a traditional PC monitor. This makes flesh tones pop, though blue hues and metals can look a little drab.
A gamma curve of 2.2 (no more, no less) is what we optimally want to see.
Nexus 5 has a calibrated gamma of 2.06, which is actually quite decent. It's somewhat lower than Tegra Note's 2.095, while the iPhone 5s is closer to the ideal with 2.19.
Our volume measurements are compared against both the sRGB and AdobeRGB color gamuts. A reading of 100% on sRGB and 72% on AdobeRGB is the optimal reading for viewing the vast majority of consumer digital content.
The Nexus 5 really impresses here with over 104% of the sRGB color gamut and an incredible 73.7% of AdobeRGB. These figures place it solidly ahead of most devices tested, including the far more expensive iPhone 5s and HTC One. Indeed, a fantastic showing for this phone, and one that proves a cheaper device can deliver a truly premium experience.