Canon EF600mm f/4L IS III USM Instructions Manual page 13

Focus Preset
Two Presets
Hold down the focus preset button to preset two
focusing distances.
< Preset the Focusing Distance >
Focus the lens at a focusing distance you
want to preset.
Hold down the focus preset button (at least
1 second), and then immediately turn the
playback ring left or right to preset the
distance in memory for that direction.
Use the same steps to preset another distance.
< Shoot at the Preset Focusing Distances >
Turn the playback ring left or right to move the
focus to each of the preset distances.
Press the shutter button while the playback
ring is turned to shoot at that distance.
Beep Sounds (Beeper)
・ Two beeps (slow): When button held down
・ One beep:
When presetting a focusing
distance
・Two beeps (fast): When the focus moves to
the preset focusing distance
Focus preset button
Hold
down
Focus preset switch
Playback ring
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