What is the brightness limit? (two)

As for the working surface of the work, the brightness of the background should be lower than the operating surface brightness, but should not be lower than the L / 3. The brightness of more than figure 3 - 6 parallelogram, the greater the chance of glare, so the parallelogram decided indoor lighting range good visual function need, also is the object, lamps, wall and top brightness must be set in this line. The best illumination in different environments, the illuminance value is basically the same. However, the optimal brightness of the observed object is not a constant, but is related to the reflectance of the surface. If the reflection ratio is low, it can be considered that the surface of the observed object is satisfied with the brightness of the object. It is often said that a theory is that the reflection ratio is reduced by half, and the illumination should be doubled.