When I saw it for the second time, I realized that it was not an accident.
The third time I armed myself with a camera and a spectrometer.
During the day, the color temperature of lighting on the Moscow 2020 train is about 4000K.
At exactly 4:00 pm, the lighting automatically becomes slightly warmer. In the photo it is almost imperceptible.
The color temperature changes by only 500K: about 4000K during the day, 3500K in the evening.
I don’t know when the reverse change takes place - probably at night.
The light in the new trains is quite high quality: the CRI (Ra) color rendering index is more than 85, there is practically no light ripple.
As you know, warm light promotes relaxation, and cold light concentration. Warm light in the evening helps a person to rest better, cold light during the day - better to work. However, I strongly doubt that the difference of 500K affects anything.
I wonder what kind of "lighting maniac" designed this train. It was necessary to install two types of LEDs in all the luminaires and make a control system with automatic switching of the color temperature by the clock.
I also wonder if there is at least one metro worker who knows about this switch? ;)
Well, also, do you think there is at least one metro passenger, besides me, who noticed the change in color temperature and realized its regularity? ;)
PS I was surprised to learn that the black color of the trains and the huge inscriptions are the film with which all trains were pasted over. And under the film they are white with blue stripes.
© 2021, Alexey Nadezhin