Nikon D780 DSLR Camera (Body Only) - Manual (Page 766)

720 Menu Guide > N The Retouch Menu
Create small copies of selected photographs. If two memory
cards are inserted, you can choose the card used to store the
resized copies.
Resizing Multiple Images
If you accessed the retouch menu via the G button, you can
resize multiple selected images.
1
Select [Resize] in the retouch
menu.
Highlight [ Resize ] and press 2 .
Resize
G button
U N retouch menu