Canon REBEL SL1 EOS 100D Instruction Manual page 38

Troubleshooting Guide
Make sure the card is properly inserted (p.32).
Slide the card's write-protect switch to the write!erase position (p.32).
If the card is full, replace the card or delete unnecessary images to
make space (p.32,268).
If you try to focus in the One-Shot AF mode while the focus
confirmation light <0> in the viewfinder blinks, a picture cannot be
taken. Press the shutter button halfway again to refocus automatically,
or focus manually (p.43, 107).
If a card error message is displayed, see page 34 or 343.
Set the lens focus mode switch to <AF> (p.40).
To prevent camera shake, press the shutter button gently (p.42, 43).
If the lens has an Image Stabilizer, set the IS switch to < ON >.
In low light, the shutter speed may become slow. Use a faster shutter
speed (p.114), set a higher lSO speed (p.98), use flash (p.111), or use
a tripod.
Set the AF operation to One-Shot AF. Focus lock is not possible in the
AI Servo AF mode, or when servo takes effect in AI Focus AF mode
(p.103).
333