Canon EOS 80D - Manual (Page 484)

Troubleshooting Guide
484
 Set the lens’s focus mode switch to <AF> (p.47).
 Press the shutter button gently to prevent camera shake (p.49-50).
 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.192), set a higher ISO speed (p.148), use flash (p.228, 233),
or use a tripod.
 Depending on the attached lens, the number of usable AF points and
patterns varies. The lenses are categorized into eight groups from A to
H. Check which group your lens belongs to. Using a lens in Groups E
to H will have fewer usable AF points (p.130-131).
 Regarding lighting up or blinking of the AF points when you press the
<S> button, see page 123.
 The AF points light up in red only when focus is achieved in low-light
conditions.
 In Creative Zone modes, you can set whether to have the AF points
light up in red when focus is achieved (p.424).
The image is out of focus or blurred.
There are fewer AF points.
The AF point is blinking.
The AF points do not light up in red.