Black and White Photography

   
The spot metering pattern is great for taking very specific readings of small
portions of the image area, particularly if your main subject is darker or lighter
than the rest of the scene—for example, a brightly lit musician against a dark
stage at a concert or an indoor subject silhouetted against a window.
Handheld spot meters also are available. These are widely used by craft
oriented medium- and large-format photographers who are especially fussy
about their exposure. Most handheld spot meters take a reading from an even
smaller area (a narrower angle) than in-camera spot meters. For example, a
camera’s spot meter may read a 5º angle of light whereas a handheld spot meter
might read 1º or less.
Once you understand the factors that lead to good film exposure, you are ready
to actually set f-stops and shutter speed—or to interpret or override the choices
that the camera makes for you, when necessary. This section describes a number
of ways to choose settings and various methods to deal with tricky photographic
situations that can make achieving good exposure difficult.
Exposure Modes
Metering patterns are the meter’s method of analyzing the light from a scene
for good film exposure. But it’s the exposure mode that determines how a
suitable f-stop and shutter speed are set. Most modern 35mm cameras (and
many medium-format models) offer a variety of exposure modes; most commonly
manual exposure, program autoexposure, aperture-priority autoexposure,
shutter-priority autoexposure, subject-program autoexposure.
Keep in mind that the various exposure modes are only options. You may
find that you consistently prefer one or another or that you use different modes
for different situations. Whatever you choose, each mode used correctly (and
adjusted, if necessary) should yield the correct exposure.
Depending on your camera, you set the exposure mode in different ways.
Many cameras have a dial on the top deck of the camera body, and you simply
turn a marked dial to set the desired mode. Other cameras show exposure
modes in an LCD display on the top of the camera body. Push a button or turn
the control wheel to get to the desired mode. Different cameras use different
display systems, but most will show the chosen exposure mode somewhere
along the edge of the viewfinder.
Manual exposure mode (M). The “M” setting stands for manual exposure mode
on most cameras. In this mode, you set both the f-stop and shutter speed yourself,
guided by recommendations from the light meter. The camera’s meter is
linked to the lens aperture and shutter speed controls; as you set different combinations of f-stop and shutter speed, you can see results displayed in the
viewfinder or LCD panel, guiding you to correct exposure.
The following methods of displaying exposure in manual mode are most
common. But the system on your particular camera might be slightly different
than that on another, so refer to your camera’s instruction book if in doubt.
Match-needle systems are usually displayed on one side of the viewfinder. As
you change f-stop or shutter speed, one or two needles move. You know you’ve
achieved the recommended exposure when the two needles match up or when
the single needle lines up to a notch or gap in the middle of the side on the
viewfinder.
LED display systems have different types of illuminated displays, such as
plus and minus signs with a circle between them, a pair of arrows, or some
other indicator on one side of the viewfinder. As you set different f-stops and
shutter speeds, the pluses, minuses, circle, or arrows light up. Recommended
exposure is generally indicated when the circle is the only lit mark, or when the
plus and minus signs or the two arrows light up at the same time.
Some cameras in manual exposure mode display a scale of f-stops, illuminated
in the viewfinder and/or on the camera’s external LCD panel, if there
is one. They also may show the selected f-stop and shutter speed. Changing
f-stops and shutter speeds moves an arrow or other mark along this scale. The
recommended exposure is indicated when the arrow reaches a center point.