Page 53 - (DK) Advanced Photography Guide

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Exposure circle
The three main exposure variables have a reciprocal
relationship—that is, if one is altered, at least one of
the others must also be adjusted to maintain the
same degree of exposure. For example, you have
two choices if you want to increase the shutter
speed but maintain the same level of exposure: you
can either make the aperture larger, reducing the ▲ Fast shutter speed ▲ Slow shutter speed
depth of field, or increase the ISO, adding image SHUTTER SPEED
noise. Exposure often involves making compromises, The shutter is a mechanical curtain that controls
particularly in low light, when you have fewer how long the camera’s sensor is exposed to light. Increase
options. Once you understand the the shutter speed by one stop, and you halve the
consequences of altering each length of time the shutter is open; reduce
1/60
1/30
setting, you will be able to S H U T T E R S P E E D the speed by one stop, and the
1/125
length of time doubles. The shutter
1/15
judge what you have to 1/250 1/8 speed you select also has an
change to achieve—or effect on how much blur
avoid—certain results 1/500 BLUR 1/4 you will get in a photo of
before pressing the LESS LIGHT MORE a moving subject. Each unit
is a fraction of a second.
shutter button. 100 LESS MORE f/32

MORE f/22
LESS
EXPOSURE LESS
200
LESS
ISO 400 f/16 APERTURE
LIGHT
This setting determines NOISE LIGHT DEPTH OF FIELD E The aperture is a variable
how much the signal I 800 MORE f/11 R opening in the lens that
S
from the sensor is O MORE T U controls how much light
amplified to create an 1,600 MORE LESS f/8 R passes through it to make an
acceptable image based on E exposure. The amount of light
the light available. You should 3,200 f/5.6 A P that it lets through halves each
use high ISO values (800 and time that the aperture is made
above) in low light, but they will 6,400 f/4 smaller by one stop, and doubles
12,800 f/2.8
increase image noise, or graininess, in each time that it’s made larger by one
the photo. In bright daylight, you can set an stop. The higher the f-stop, the smaller the
ISO of 80 or 100. For the best image quality, use the aperture. The aperture also controls depth of field,
lowest setting possible (known as the “base ISO”). the zone of sharpness in the photo.

▲ High ISO ▲ Low ISO ▲ Large aperture ▲ Small aperture

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