Canon EOS R6 Mark II Mirrorless Camera with 24-105mm f/4-7.1 Lens - Manual (Page 528)

Lens operation when AF is not available
You can specify lens operation that applies when autofocusing on a subject is not possible.
[ ] Continue focus search
If focus cannot be achieved with autofocus, the lens is driven to search for the precise
focus.
[ ] Stop focus search
If autofocus starts and the focus is far off or if focus cannot be achieved, the lens drive
will not be performed. This prevents the lens from becoming grossly out of focus due to
the focus search drive.
Caution
[ Stop focus search ] is recommended for super telephoto lenses or other lenses
that are driven over a large focus area, to avoid significant delay from focus search
drive if the lens becomes greatly out of focus. Note that autofocusing will stop if the
camera determines that autofocusing on a subject is not possible, in which case
you should focus manually to bring the focus closer before autofocusing again.
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