An article in the magazine Outdoor and Travel Photography states, If a surface is illuminated by a

An article in the magazine Outdoor and Travel Photography states, €œIf a surface is illuminated by a point-source of light, the intensity of illumination produced is inversely proportional to the square of the distance separating them. In practical terms, this means that foreground objects will be grossly overexposed if your background subject is properly exposed with a flash. Thus direct flash will not offer pleasing results if there are any intervening objects between the foreground and the subject.€

If the subject you are photographing is 4 ft from the flash and the illumination on this subject is 1/16 of the light of the flash, what is the intensity of illumination on an intervening object that is 3 ft from the flash?