The index rather than the pictures: formatting clears the directory that says where files are, and writes the structure the camera expects. The data itself is overwritten later, which is why recovery is sometimes possible and never guaranteed.
Formatting is a bookkeeping operation, and understanding that explains both why it is fast and why recovery is occasionally possible.
What happens
The file system’s index is rewritten. Afterwards the card reports itself empty because nothing points at the old files, and the camera’s own directory structure is in place. What is not done is scrubbing every block — that would take far longer than the operation does.
The consequence in two directions
For recovery: until the blocks are reused, the data is still there and software can often reconstruct it. Taking more pictures is what destroys it.
For disposal: a formatted card is not a wiped card. Anything sensitive needs a secure erase or physical destruction, and no camera menu offers the first.
Where it belongs in the setup
Among the four things worth doing on a new body: the date, the file format, the card formatted in the camera, and the firmware note read rather than the version number chased.
What no figure covers
How many times a card can be formatted, and how it will fail. Neither is published, which is the practical argument for two cards rather than one — a habit, not a specification, and this site does not dress it as one.
What people ask before they commit
So can I recover photographs after formatting?
Sometimes, if nothing has been written since — the blocks still hold what they held, without an index pointing at them. The moment you take more pictures, some of those blocks are reused. The practical rule is to stop using the card immediately and treat recovery as a possibility rather than a plan.
Why format in the camera rather than on a computer?
Because the camera writes the directory layout it expects and clears anything it does not recognise. A card formatted elsewhere can work and still produce odd behaviour, and makers publish the instruction for that reason.
Last reviewed 12 September 2026