Canon EF 500mm f/4L IS II USM Instructions Manual page 9

5. Focus Preset
By presetting any focusing distance, you can instantly focus at that point even while you are
shooting a different subject. This function operates in any of the AF, PF, and MF modes.
< How to Set >
Set the focus preset switch
to ON or .
Press the shutter button
halfway to focus the
distance you want to preset.
Press the focus preset
button.
The focused distance will be
O O
preset.
If the focus preset switch was
O O
set to , the beeper will
sound once.
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