Correct Answer and Feedback
Just as f/4 produces two times as much light as f/5.6, a light 4 feet away will be two times
as intense as one at 5.6 feet. For a 3:1 ratio, this would then be the proper distance for the
light (4 feet for main, 5.6 feet for fill) (page 17, para 13b).
Adjust the light from the flash so that it is about one stop less than the overall
When using fill-in flash outdoors as supplemental light to the already existing daylight,
you must consider exposure from both of these light sources. Setting the flash about one
stop less than the reading for the ambient light will give a natural appearance to the
lighting (page 18, para 14e).