(b)
Use the following
formula
to
calculate
the
corrected
exposure setting (CES):
BE 2
CES = ( FL ) x EM
Where:
CES is the corrected exposure setting in seconds.
BE is the bellows extension distance in inches.
FL is the focal length of the lens in inches.
EM is the exposure meter setting in seconds.
EXAMPLE:
The camera lens has a 12-inch focal length which is
operating with a bellows extension of 27 inches. The exposure meter indicated
that an exposure of 7 seconds at f/22 would be correct for the illumination and
the film used. Using the formula, find the corrected exposure setting (CES).
BE 2
CES = ( FL ) x EM
27 2
CES = ( 12 ) x 7
729
CES = 144 x 7
CES = 5.06 x 7
CES = 35.4 seconds
(Therefore, the corrected exposure setting is 35 seconds at f/22).
(4)
Upon completion of the corrected exposure setting calculation,
set the aperture lever at the required f/stop (b(1) above), set the speed
cam at T, and make the copy.
73
Previous Page
