SD memory chips are one of the most popular used in digital cameras. They are normally very reliable, but occasionally photos can be lost through corruption, or physical failure.

Corruption

The most common form of failure is due to either logical corruption, or accidental deletion. The corruption is typically the FAT map is overwritten with a file. This can be caused by a hiccup in the camera, or when the chip is moved into a card reader. The result is that the chip is recognised, but the error message that the chip is not formatted will be displayed. The CnW Wizard will analyze such a chip and probably suggest a Raw recovery. At other times it may manage to recover enough information to perform a standard read. Fortunately, if a Raw recovery is required, the software will generate file names based on the camera name, and date of the photo. This will make sorting very easy.

 Physical failure

Physical failure is rare, and it can occur in two ways, a complete failure, or just a few sectors. If a memory chip can not be recognised by the computer in anyway, then it could be a complete physical failure, for which there is nothing that can be done in software alone. Before giving up though, one should always try a new card reader.

Partial failure is when a few sectors fail. For this CnW software is very tolerant at reading and many photos will be recovered