Reference Manual

342 Menu Guide > N The Retouch Menu
D Image Overlay
Only NEF (RAW) photographs with the same image area and bit-depth
can be combined. The overlay is saved in JPEG fine format and has the
same photo info (including date of recording, metering, shutter speed,
aperture, shooting mode, exposure compensation, focal length, and
image orientation) and values for white balance and Picture Control as
the photograph selected for Image 1. The current image comment is
appended to the overlay when it is saved; copyright information,
however, is not copied.