Canon EOS 7D Instruction Manual page 245

The image is out of focus.
Set the lens focus mode switch to <AF> (p.31).
To prevent camera shake, hold the camera still and press the shutter
button gently (p.34, 35).
If the lens has an Image Stabilizer, set the IS switch to <1>.
The card cannot be used.
If a card error message is displayed, see page 30 or 249.
The maximum burst during continuous shooting is lower.
Set [8C.Fn II -2: High ISO speed noise reduction] to one of the
following settings: [Standard/Low/Disable]. If it is set to [Strong], the
maximum burst during continuous shooting will decrease (p.208).
If you shoot a subject which has fine detail (field of grass, etc.), the file
size will be larger and the actual maximum burst will be lower than the
number mentioned on page 59.
ISO 100 cannot be set.
If [8C.Fn II -3: Highlight tone priority] is set to [Enable], ISO 100
cannot be set. If [Disable] is set, ISO 100 can be set (p.209).
When I use the <f> mode with flash, the shutter speed becomes slow.
If you shoot at night when the background is dark, the shutter speed
becomes slow automatically (slow-sync shooting) so that both the
subject and background are properly exposed. If you do not want a
slow shutter speed to be set, set [8C.Fn I -7: Flash sync. speed in
Av mode] to 1 or 2 (p.207).
Troubleshooting Guide
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