Nikon D780 DSLR Camera (Body Only) - Manual (Page 619)

573 Menu Guide > 1 The Movie Shooting Menu
Choose the image area for movies.
Auto DX Crop
Choose whether the camera automatically uses the [ DX ] image
area for movies recorded with a DX lens.
Choose the movie frame size (in pixels) and frame rate. For more
information, see “Frame Size/Frame Rate and Movie Quality”
(
0 264).
Image Area
G button
U 1 movie shooting menu
Frame Size/Frame Rate
G button U 1 movie shooting menu