First, let’s look at the environmen

First, let’s look at the environment itself. There are many factors that influence how dark a night will be -
which in turn dictates what if anything you might need to use to counter the darkness.
Moon
The moon is the most dramatic natural
influence on nighttime visibility - when it’s full
and high in the sky, you’ll find the terrain to be
well-lit and visibility to be good even without
the use of any special equipment. The moon
provides illumination in a similar manner to the
sun - except obviously not nearly as bright.
Light from the moon will cause shadows on
the ground, while the phase of the moon will
dictate how much illumination is provided.
“New” moons give little, full moons more, while
the positioning in the sky plays another part
and determines the length and direction of
shadows.