Night and Low-light Photography Photo Workshop

frozen in place, then you can increase the

shutter speed and the camera will automati-

cally try to open the aperture wider. If you

want to adjust the aperture so that you get the

desired depth of field, the camera will auto-

matically adjust the shutter speed so that the

exposure is correct. Check your camera man-

ual for how to adjust the settings when in pro-

gram auto mode.

    ■   Shutter speed priority mode. When you use

the shutter speed priority mode, you set the

shutter speed, and the camera uses the built-in

light meter to determine what the best aper-

ture is to get a proper exposure. This is useful

if you want to control the shutter speed to get

the desired results. For example, if you really

want to make sure that you are freezing the

action, and the depth of field is less important,

then you want to use this setting and set the

shutter speed as high as needed. The camera

will then try to use the smallest aperture it

can to get the proper exposure until it is at

the widest aperture for the lens used.

Exposure modes

Your camera has at least four basic exposure
modes and quite possibly many more. The four
basic exposure modes are program auto, shutter
speed priority, aperture priority, and manual.
They are labeled P, S, A and M on Nikon and
Sony cameras and P, Tv (for Time value), Av
(for Aperture value), and M on Canon cameras.
These modes determine what happens when you
press the shutter release button.

■   Program auto mode. This is the automatic

mode of your camera; it gives most of the
control to the camera’s built-in light meter.
When you press the shutter release button
halfway down, the camera’s built-in light
meter reads the light in the scene and picks
the best aperture and shutter speed (and in
some cases, the ISO as well) so that the image
is properly exposed. What makes this different
from a fully automatic mode is that you can
still adjust the settings before actually taking
the photo. If you decide that you need a faster
shutter speed to make sure the subject is

ABOUT THIS PHOTO

The Marine Color Guard was

present at the start of the Rock

‘n’ Roll Marathon in San Diego,

and I needed to push the ISO

because it was early in the

morning and there wasn’t a lot

of light present. Taken at 1/60

second, f/3.2, and ISO 1250.

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