How difficult it is to compare LCD to AMOLED screens
The resolution pursuit keeps dragging on in the smartphone ecosystem. Nowadays is getting difficult to impress only by adding more pixels into a display. With 2560×1440 transforming into the basic standard for flagship screen resolution, we have to think about how to isolate the weak from the strong.
It is not difficult to measure resolution; brightness is what raises difficulties, especially when we talk about AMOLEDs. Also, there is a sort of dispute about how to establish AMOLEDs display brightness and who obtained the right numbers. As an example, we have Anandtech who stated the Nexus 6 display brightness reached at 258 nits, while other devices have listed 400 nits as the peak of brightness. So, we may wander who is right, but the truth is everyone might be right in their own way.
LCD and AMOLED are two distinct types of display technology regularly used in smartphones. LCD represents an older technology. LCDs use banks of LEDs to direct light through the liquid crystal setting in order to provide the desired effect. These LEDs have upper limit brightness and the quantity of light that can reach the user is led by the size and number of pixels.
AMOLEDs represent the new technology and have become popular in many of the top smartphones. Calculating the brightness for these is not an exact process because of the fact that AMOLEDs have a distinct way to produce light. It does not have a special backlight because the photons are obtained directly by each subpixel, which has the capability to shine red, blue or green when voltage is applied. So, if your goal is to display black, the AMOLED pixels are turned off. This represents the main advantage of AMOLED technology: it requires less power in order to provide black images.
The difficulty comes from calculating AMOLED brightness because of the image used.They differ from LCDs because there is no maximum brightness for an AMOLED pixel. AMOLED has a special feature called Average Pixel Level (APL) which represents the amount of pixels that are lighted expressed as a percent. So, for a black screen we have 0%, for a white 100% and red, green or blue would be around 33%. Low APL means that the display distributes more power to individual pixels so they can offer more light in the lit area.
Bottom line it is achievable to obtain higher brightness levels with an AMOLED. Anyway, in daily use the majority of images have really high APL. This is sustained especially by Android 5.0, which possesses more white UI elements. This means that the Lollipop`s settings screen reaches about 84% APL. Also, keep in mind the fact that in real life there might be 20% more brightness than what reports say. This means that the 400 nits for the Nexus 6 are truly not realistic. So, for sure the truth can be found somewhere in between.