Canon REBEL SL1 EOS 100D Instruction Manual page 42

Troubleshooting Guide
If you use flash, the shutter will make two sounds each time you shoot
(p.151).
Depending on the shooting conditions, focusing the subject may take
longer. Either use FlexiZone - Single or focus manually.
It indicates that the camera's internal temperature is high. If the white
<_> icon is displayed, the still photo's image quality may deteriorate.
If the red <H> icon is displayed, it indicates that the Live View or
movie shooting will soon stop automatically (p.178, 212).
If the card's writing speed is slow, movie shooting may stop
automatically. Use an SD Speed Class 6 "OLASS(_" or faster card. To
find out the card's reading/writing speed, refer to the card
manufacturer's Web site, etc.
If the movie shooting time reaches 29 min. 59 sec., the movie shooting
will stop automatically.
In shooting modes other than <M>, the ISO speed is set
automatically. In the <M> mode, you can freely set the ISO speed
(p.186).
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