Nikon Z 9 Reference Manual page 504

D
Caution: [RAW Slot 1 - JPEG Slot 2]
If [ON] is selected for [Multiple exposure] > [Save individual pictures
(RAW)] in the photo shooting menu, or if [ON] is selected for [HDR
overlay] > [Save individual pictures (RAW)] in the photo shooting menu,
unprocessed copies of the individual NEF (RAW) photos that make up each
multiple exposure or HDR picture will be recorded to both memory cards
together with the JPEG composite, regardless of the option selected for
image quality.
A
[Backup], [RAW Slot 1 - JPEG Slot 2], and [JPEG Slot 1 - JPEG
Slot 2]
•
The shooting display and control panel show the number of exposures
remaining on the card with the least amount of space available.
•
The shutter release is disabled when either card is full.
A
Viewing Dual-Format Photos
•
Use the [Dual-format recording PB slot] item in the playback menu to
choose the slot from which dual-format photos are played back.
•
When viewing dual-format photos, you can view the other copy using
[Jump to copy on other card] in the i menu.
A
Recording Videos
The slot to which videos are recorded is selected using [Destination] in the
video recording menu.
C The Photo Shooting Menu: Shooting Options
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