Canon EOS 600D - Manual (Page 280)

Troubleshooting Guide
280
If a card error message is displayed, see page 30 or 287.
If the card already contains recorded images, the image number might
not start from 0001 (p.170).
Set the lens focus mode switch to <AF> (p.36).
To prevent camera shake, press the shutter button gently (p.39, 40).
If the lens has an Image Stabilizer, set the IS switch to <1>.
In low light, the shutter speed may become slow. Use a faster shutter
speed (p.94), set a higher ISO speed (p.79), use flash (p.90), or use a
tripod.
Horizontal stripes or irregular exposures can be caused by fluorescent
light, LED bulbs, or other artificial lighting during viewfinder or Live
View shooting. Also, the exposure or color tone might not come out
right. A slow shutter speed may solve the problem.
The card cannot be used.
The file numbering does not start from 0001.
The image is out of focus.
Horizontal stripes appear, or the exposure or color tone look
strange.