Nikon F4 - Manual (Page 116)

• To cancel self-timer operation, turn the film advance mode
selector to another setting.
• In self-timer operation, the shutter is released whether the
subject is in focus or not, even in the Single Servo Autofocus
mode, so lightly press the shutter release button first while
aiming the camera at the subject to secure correct focus.
• Exposure is continually monitored during self-timer operation
until just before the shutter fires. Use of eyepiece shutter or
eyepiece cover is recommended.