Canon EOS 20D Instruction Manual

49

The ISO speed is a numeric indication of the sensitivity to light. A higher 
ISO speed number indicates a higher sensitivity to light. Therefore, a 
high ISO speed is suited for low light and moving subjects. However, the 
image may look more coarse with noise, etc. On the other hand, a low 
ISO speed is not suited for low light or action shots, but the image will 
look cleaner. The camera can be set between ISO 100 and 1600 in 1-
stop increments.

The ISO speed is set automatically within ISO 100-400.

You can set the ISO speed to “100”, “200”, “400”, “800”, or “1600”. With 
C.Fn-08 [ISO expansion] set to [1: On] (p.143), “H” (ISO 3200) can 
also be set.

R> button. 

(

9)

s

The current ISO speed will be 
displayed on the LCD panel.

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In a Basic Zone mode, “Auto” will be 
displayed on the LCD panel.

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While looking at the top LCD panel, 
turn the <

5> dial.

g Setting the ISO Speed

N

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At higher ISO speeds and higher ambient temperatures, the image will 
have more noise.

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High temperatures, high ISO speeds, or long exposures may cause 
irregular colors in the image.