Nikon D3S - Manual (Page 157)

131
Z
❚❚Aperture Lock
To lock aperture at the selected value, press the F button and
rotate the sub-command dial until F icons appear in the
viewfinder and the top control panel.
To unlock aperture, press the F button and
rotate the sub-command dial until the F
icons disappear from the displays.
Sub-command dial F button
SHOOT
CUSTOM