Children's Portrait Photography Handbook

Since they reflect the difference in intensity between the
main light and the fill light, the ratio is also an indication
of how much shadow detail you will have in the portrait.
Calculating.There is considerable debate and confu-
sion over the calculation of light ratios. This is principally
because your have two systems at work, one arithmetical

and one logarithmic. F-stops are in themselves a ratio be-

tween the size of the lens aperture and the focal length of

the lens, which is why they are expressed as f/2.8, for ex-

ample. The difference between one f-stop and the next

full f-stop is either half the light or double the light. For

example f/8 lets in twice as much light through a lens as

This is a beautifully executed portrait of three sisters by Brian Shindle, who used a single large softbox to the left of the camera and a
large white reflector to the right of the camera. A diffused hair light was used from above. Brian removed the second set of catchlights
in the eyes and reshaped the rectangular catchlights to form a circular pattern, giving the image a more traditional feel.