Plants respond to the length of day and to the amount (intensity) of light received during the day. Each species, maybe even each plant, has its own minimum amount and maximum amount of daily sunlight accumulation. On sunny days, light intensity varies over time, as the sun travels from east to west. It is possible to have 900 fc in the morning, 6000 fc at noon and 900 fc in the evening with a waxing and waning in between. Also, bright full June sunlight is more radiant than bright full March sunlight. One must consider location as well. Toronto receives more of a glancing blow (less radient) from the sun while Florida gets hit on the top of the head. I gather that light exposure is cumulative. There are a couple of ways to consider exposure. One way is to estimate the percentage of the day that the plant receives the 6000 fc. Another way (photoperiodism) is to calculate exposure over time. Light intensity (measured in foot-candles) times the duration of the light intensity (measured in hours of exposure) equals foot-candle hours. A schefflera supposedly prefers bright light with some direct sunlight: a daily accumulation of 20,000 to 35,000 fc/hrs in the spring and 25,000 to 65,000 fc/hrs in the summer. An african violet likes spring 10,000 to 20,000 fc/hrs and summer12,000 to 25,000 fc/hrs.