NightDimly lit scenes, in the real world, have characteristic washed-out colors. Objects that are bright red in daylight appear to be soft pink in moonlight. This desaturation is a result of the way the two types of light receptors in the human eye work: in bright lighting conditions the color-sensitive cones provide the information we receive, but in darker conditions the achromatic rods begin to take over, giving us much less color information - which thereby makes objects appear desaturated. The Night shader simulates their effect.
Select Night as the lens shader.
Edit Night's parameters.
Night works by boosting dim lighting, while keeping the colors desaturated - similar to the way the human eye behaves. The artist chooses by how much to boost the dim light with the Multiplier parameter, and defines what Night should consider dim lighting, i.e. under what light level it will begin to boost / desaturate, with the Cutoff parameter.
When designing a nighttime scene, it is essential that Night be activated before lighting is set. Night has a significant effect on dim lights: what looks good before activating Night will need to be adjusted after activating Night.
It should be noted that Night simulates the way human eyes work in dim lighting, and not the way a camera captures dimly lit images; do not use Night if the rendered image is intended to mimic a photographic look.