Canon REBEL T3I EOS 600D User Manual page 283

The shutter makes two shooting sounds during Live View
shooting.
If you use flash, the shutter will make two sounds each time you shoot
(p.125).
During Live View and movie shooting, a white <s> or red
<E> icon is displayed.
It indicates that the camera's internal temperature is high. If the white
<s> icon is displayed, the still photo's image quality might
deteriorate. If the red <E> icon is displayed, it indicates that the Live
View or movie shooting will soon be terminated automatically (p.139,
163).
Movie shooting terminates by itself.
If the card's writing speed is slow, movie shooting may stop
automatically. Use an SD Speed Class 6 "
find out the card's read/write speed, see the card manufacturer's Web
site, etc.
The movie shooting will be terminated automatically if the file size
reaches 4 GB or if the movie length reaches 29 min. 59 sec.
The image flickers or horizontal stripes appear during movie
shooting.
Flickering, horizontal stripes (noise), or irregular exposures can be
caused by fluorescent light, LED bulbs, or other artificial lighting during
movie shooting. Also, changes in the exposure (brightness) or color
tone might also be recorded. With manual exposures, a slow shutter
speed may solve the problem.
Troubleshooting Guide
" or faster card. To
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