2 Basic exposure
In the good old days of photography, determination of exposure used
to be achieved by a combination of hard practical experience and a
sort of mystical intuition. The photographer would momentarily
retire into the silences of his soul and emerge with the message,
“One twenty-fi fth of a second at f/11”—which surprisingly often
turned out to be right.
—William Mortensen
Mr. Mortensen wrote those words in 1950 but they could have
just as well been written today! Whether shooting fi lm or digital,
one common factor remains important for both methods of
capture: correct exposure is critical; maybe even more so for
digital than for fi lm, especially color negative fi lm. That’s
because the latitude (the ability to over- or underexpose an
image) is greater with color negative fi lm than for any other
capture media. Slide fi lm has the least amount of latitude, espe-
cially on the overexposure side. Digital camera imaging sensors
respond more like a hybrid of the two different kinds of color
fi lm: overexposure wipes out image data, but underexposure has
more latitude, almost as much as fi lm. The downside of digital
underexposure is the inevitable creation of noise, especially in
shadow areas, or what you might see in a photograph that appears
to be digital “grain.” (More on noise and how to get rid of it in
