Why doesn’t Spyder X Elite / Spyder X Pro / Spyder5 software define a brightness for my laptop screen as part of calibration?
Mobile devices such as laptops and convertibles are viewed under a wide range of light levels. Ambient light adjustment of the device at the time of calibration would only be of value if such a device were to remain in the same controlled light environment, as a desktop display in an editing lab does. Outside of such a situation, the user is expected to adjust the mobile screen to an appropriate level for the current lighting. This is why there is no room light related adjustment to the screen's brightness in the laptop mode of Spyder X Elite / Spyder X Pro / Spyder5.
However, viewing in an environment where other light sources are brighter than the mobile screen will cause the eye to be white balanced to the ambient conditions, not the screen, so that the mobile screen will look “wrong” to the eye. So, in addition to adjusting screen brightness appropriately for the ambient condition on mobile devices its also important to recognize situations where the screen’s brightness is overwhelmed by other light sources, and to realize that color will not look correct on screen, when the screen is not in control of the eye’s white balance.