D4: Exposure Delay Mode; D5: Electronic Front-Curtain Shutter; D6: Limit Selectable Image Area - Nikon Z 7 Reference Manual

d4: Exposure Delay Mode

In situations where the slightest camera movement can blur
pictures, shutter release can be delayed by from about 0.2 to
3 seconds after the shutter-release button is pressed.

d5: Electronic Front-Curtain Shutter

Select Enable to enable the electronic front-curtain shutter,
eliminating blur caused by the motion of the mechanical
shutter.
D
The Electronic Front-Curtain Shutter
The fastest shutter speed and maximum ISO sensitivity available with
the electronic front-curtain shutter are
51200 (Z 6), respectively.

d6: Limit Selectable Image Area

Choose the options available when
image-area selection is assigned to the i
menu or to the command dials and a
camera control. Highlight the desired
options and press 2 to select or
deselect. Press J to save changes when
settings are complete.
260 Menu Guide > A Custom Settings
G button ➜ A (Custom Settings menu)
G button ➜ A (Custom Settings menu)
/
1
s and ISO 25600 (Z 7) or
2000
G button ➜ A (Custom Settings menu)