Nikon D300 Complete Manual page 125

V1.02
Solution: One of several problems is likely present on the
card: (1) the FAT (File Allocation Table, which tracks clusters
in use) is corrupt; (2) the directory has incorrect information
about files, usually either cross links of data between two
images or missing cluster information; or (3) something else is
wrong with the data or structure on the card, such as a
damaged sector, an incomplete file, an unexpected End-of-
File marker, and so on. In every case, you must immediately
fix the problem or risk the permanent loss of your image data.
You may or may not be able to fix the problem, but if
anything gets written to the card before you begin attempting
a correction, your ability to recover data is compromised.
Macintosh users should be extremely careful when mounting
problematic cards on their computers, as several behind-the-
scene tasks can write to the card without your knowledge.
So how do you fix the structure and data and recover your
images? The best choice is to use a product such as Photo
Rescue (http://www.datarescue.com/photorescue). This tool—
versions are now available for both Macintosh and
Windows—generally can find and recover images that are the
result of most structure errors, though you may have to go into
the advanced mode and play with some of the settings in
order to do so. Current versions of Photo Rescue understand
the NEF format, and can resurrect a raw data file, complete
with the proper extension. If you haven't written anything to
the card after the error occurred, you can often recover every
image on the card. Note that to use Photo Rescue you need a
way to mount the card either by inserting the card into a
PCMCIA adapter on a portable, or by putting the card into a
card reader attached to your desktop machine.
Personally, I travel with Photo Rescue installed on my laptop
and with a card reader so that I can recover images from
cards, when necessary.
Problem: Images you shot don't seem to be recorded on the
card. Recovery software finds no record of them, and the file
numbering seems sequential.
Thom Hogan's Complete Guide to the Nikon D300 Page 125