First equip the binoculars, then quick unequip. Enter a tight space, like a vent, and as SOON as the camera begins to move into 'Intrusion Mode' aka First Person immediatly equip the binoculars. You will continue to move forward WITH the binoculars equiped, but you will not be able to control Snake at all, except to unequip the binoculars, which will then return everything to normal.