Nikon Autofocus Speedlight SB-22 Instruction Manual page 31

3,Set SB-22's mode selector
'to A1 or A2 according to
the selected aperture.
24
^ Set your chosen aperture.
' With Nikon F-401/N4004, use
camera's aperture dial.
Next turn on flash unit and take
shot in the same manner shown
in "BASIC OPERATION," steps 10
to 14.