I'm surprised it wasn't highlighted in every review that the Nexus 6P sunlight legibility is poor, for 4 main reasons:
– The automatic brightness at its default settings doesn't adjust to ambient lighting conditions enough.
You have to slam the auto brightness offset slider manually to the maximum so it reaches the maximum brightness allowed.
It is either a defect of the light sensor of my unit or a bug that may need to be filed.
– The amount of internal reflections in the panel is high in today's standards, in no way comparable to an LPTS LCD of the two years old Nexus 5 and its polarized lens generation.
– The maximum brightness allowed by the AMOLED panel driver (measured at 366 cd/m² on my unit) is below average nowadays. Most mid-range smartphones reach higher brightness levels.
– The gamma curve is nearing a 2.4 average at higher brightness levels (it is rarely constant on AMOLEDs)
It makes every color but white itself darker than it should, which only reduces legibility further in challenging environmental conditions.
Conclusion:
Bugs, limited hardware characteristics and inadequate calibration together make up one of the poorest sunlight legibility in today's smartphones on the Nexus 6P.
Concretely, it means that if you're used to walk out, exchange message, read articles, you will struggle doing so on the Nexus 6P despite the larger screen.
Some of the shortcomings could be addressed to improve the situation.