Young Curly Brunette Girl Undresses A Black Bikini Bra In The Sand On A Sunny Day

Direct sunlight has a luminous efficacy of about 93 lumens per watt of radiant flux. Bright sunlight provides illuminance of approximately 100,000 lux or lumens per square meter at the Earth's surface.
Sunlight is a key factor in photosynthesis, a process vital for many living beings on Earth.