Lesson 3/Learning Event 7
c. Now correct the basic exposure for lighting directions:
Side lighting, open up one additional stop
Back lighting, open up two additional stops for close-ups
3. In each case, start with the ISO speed to determine the shutter speed,
set f/16 as your lens aperture, and open up or stop down by the required
number of stops for the lighting conditions, subject brightness and lighting
direction. Take a bright subject which is side-lit on a day with hazy-sun.
What would the effective exposure be using a film rated at ISO 200?
a. By starting with the ISO, set the shutter speed for 1/250 as this
closely matches the ISO of 200. Preset the f/stop at f/16 and determine the
lighting conditions; hazy-sun requires the aperture to be opened up one stop
from the basic exposure, so open the aperture to f/ll.
b. Now correct for subject brightness; a bright subject requires the
aperture to be stopped down one stop.
Change the aperture from f/11 to
f/16. And last, correct for lighting direction; side-light requires you to
open one stop. Open the aperture one stop from f/16 to f/ll. The effective
exposure will be 1/250 at f/11.
c. Now if you wish, you can select any exposure combination which would
equal the effective exposure of 1/250 at f/ll. For example, 1/125 at f/22,