Nikon D810 - Manual (Page 98)

74
Image Recording Options
Choose from image areas of FX (36Ч24) 1.0Ч (FX format),
DX (24Ч16) 1.5Ч (DX format), 5 : 4 (30×24), and 1.2Ч (30Ч20)
1.2Ч. See page 490 for information on the number of pictures
that can be stored at different image area settings.
Image Area
DX format (24×16)
image circle
FX format (36×24)
image circle
FX format
1.2×
5 : 4
DX format