Nikon D780 DSLR Camera (Body Only) - Manual (Page 208)

162 Shooting Settings
Manual Focus
Manual focus is available for lenses that do not support
autofocus (non-AF NIKKOR lenses) or when the autofocus does
not produce the desired results.
• AF lenses : Set the lens focus
mode switch (if present) and
camera focus-mode selector
to
M .
• Manual focus lenses : Focus manually.