noun
natural light
General term for light from the sun or other natural sources, as opposed to artificial light (人工光).
See also: 人工光
この部屋は自然光がたくさん入るので明るい。
This room is bright because it gets a lot of natural light.
noun
unpolarized light
Physics term for light whose electric field vibrates in all directions perpendicular to the direction of propagation.
自然光は偏光フィルターを通すと偏光になる。
Natural light becomes polarized when it passes through a polarizing filter.