Resize; Resizing Multiple Images - Nikon D780 Reference Manual

Resize

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 .
720 Menu Guide > N The Retouch Menu
G button U N retouch menu