How may watts to 50 foot candles?

To convert foot-candles to watts, you need to consider the type of light source and its efficiency. Foot-candles measure illuminance, while watts measure power consumption. Generally, a rough estimate is that 1 foot-candle requires about 0.1 to 0.2 watts per square foot of well-distributed light. Therefore, to achieve 50 foot-candles, you would need approximately 5 to 10 watts per square foot, depending on the light source's efficiency.