Freeze Focus
The optional Nikon Multi-Control Back MF-23 or 250-Exp. Multi-Control Back MF-24, when attached to the F4, offers a Freeze Focus function which automatically fires the shutter when the subject enters a preset focus position. This feature is especially convenient for manual focus with the F4'sElectronic Rangefinder. For details, see the MF-23 or MF-24's instruction manual.