Video Image Area Options
The image area for videos can be selected using  > [ ] in the video recording menu. The crop used for filming video varies with the option selected. Regardless of the option selected, the aspect ratio is 16:9.
Select  to shoot videos in what is referred to as “FX-based video format”, [ ] to shoot in “DX-based video format”.
Selecting  for [ ] or mounting a DX lens on the camera with [ ], [ ], [ ], or [ ] chosen for [ ] increases the apparent focal length by approximately 2.3× when compared to FX format.
The option currently selected is shown by an icon in the display. If  is chosen for [ ] > [ ] in the video recording menu, an image-area icon will flash in the shooting display when the DX or 2.3× crop is selected.
The sizes of the different crops are shown below.
FX-based video format
Approx. 35.9 × 20.2 mm
DX-based video format
Approx. 23.5 × 13.2 mm
Approx. 16.7 × 9.4 mm
DX-based video format is selected automatically when a DX lens is attached.
When 7680 × 4320 is selected for frame size, image area is fixed at . The frame size changes to 3840 × 2160 when a DX lens is attached.
Selecting  for [ ] in the video recording menu reduces the size of the crop.