What causes it
Deleting a file doesn’t erase it. The card marks the space that file was using as free and removes it from the list. The contents stay where they were until something new is written into that space.
That’s true whether you deleted one photo in the camera, used “delete all”, or dragged files to the trash on a computer.
It also means the deleted file is only safe as long as the card isn’t used. The camera sees free space and will use it for the next shot.
What to do right now
- Stop shooting on the card and take it out of the camera.
- If you deleted the files on a Mac and haven’t emptied the Trash, plug the card back in and look in the Trash. They may still be there.
- Don’t copy anything onto the card, and don’t install recovery software on it.
- Write down roughly when the missing files were shot, and how much you’ve shot since deleting them.
What’s realistically recoverable
If nothing has been written to the card since the delete, this is usually a Standard recovery.
Photos tend to come back well, because each one is small and usually stored in a single piece. Their names and folders often come back too, since deleting leaves most of the index in place.
The honest variable is how much has been shot since. A handful of frames on a large card may have touched very little. A full day of shooting may have replaced most of it. The evaluation report lists what I found by type and date range, so you can see whether the files you care about are in it.
When it isn’t
- The space has been reused. Files that were written over are gone, and no one can bring them back.
- The file was stored in pieces. When a file is deleted, the record of where its pieces were is cleared. For a photo that rarely matters. For a long video it can mean the clip comes back incomplete, or needs rebuilding, which is a Complex recovery. See recovered video that won’t play.
- The files were on internal storage, not a card. Internal storage on action cameras and drones is often unrecoverable once TRIM has run. TRIM is the device telling its storage that deleted space can be erased, and once that’s done there is nothing left to read. Tell me on the intake form if this is your situation, before you ship anything.