Production · interview production cards and drives
interview production: check a backup size mismatch
Why is the backup from the interview production smaller than the source?
Short answer
Often only the size on disk differs: a destination with larger clusters or another file system reports a different total for identical files. A real gap shows up per file, so compare filenames and exact byte sizes for each interview camera and the audio recorder separately. Keep source cards and backup unchanged until that comparison is done.
The situation
A copy exists, but byte totals or file counts do not match the recorded cards.
A backup that reports a smaller total is worth investigating per file, not per folder. Two volumes with different cluster sizes report different space for byte-identical material, so the totals can differ while every interview file is present and complete on both sides.
01 / Diagnose
Work out what actually disappeared
An interview shoot writes three parallel sets: A-camera, B-camera and the audio recorder, each with its own structure and its own hidden files. A backup that covered only the video folders looks short by exactly the WAV tree. Where a large chapter file failed to copy, the shortfall is concentrated in one clip instead of spread across many.
Hidden sidecars, failed large files, filters and allocation errors can all change totals. For interview production, this matters because the interview production combines several sources, takes and handoff steps that must be reconciled as a set
Check the last known path, trash and backups without writing to the original device.
02 / Protect the source
Preserve the best recovery chance
- 1
Keep the cards and the backup exactly as they are; no deletion, no reformatting, no second backup run for now.
- 2
Produce a per-device file list with names and byte sizes for both cameras and the recorder, then compare card and backup.
- 3
Look specifically for the largest files and for the whole audio tree, which are the two usual sources of a shortfall.
- 4
Copy every file the comparison flags from its card again and confirm the byte size at the destination afterwards.
Do not clear the cards once the folder totals look close enough, and do not overwrite the existing backup with a fresh run. A second pass with the same filter reproduces the same gap and can delete the only complete version you still have.
03 / Choose the method
Match the tool to the source
For stable, readable exFAT, NTFS and FAT16/FAT32 or uncompressed IMG, DD, RAW and BIN images.
Unconfirmed exports are marked .UNVERIFIED.
Comparing and copying again needs no licence and no recovery software. A scan becomes relevant only for files already deleted from a readable exFAT, NTFS or FAT16/FAT32 volume, and unconfirmed exports carry the suffix .UNVERIFIED until you check them yourself.
04 / Verify
Check the recovered content, not just its name
The backup holds when each camera folder and the recorder folder match their card by file name and exact byte size. Then open the longest take from the backup and play its final minute, and confirm the WAV files import into the edit at full length.
Keep the source until two verified copies exist. One working preview is not enough.
Sources and technical references
FAQ
Questions about this recovery case
Can interview production cards and drives be recovered in this situation?+
A backup that reports a smaller total is worth investigating per file, not per folder. Two volumes with different cluster sizes report different space for byte-identical material, so the totals can differ while every interview file is present and complete on both sides. The result still depends on what remains readable on the source.
What should I avoid before scanning?+
Do not clear the cards once the folder totals look close enough, and do not overwrite the existing backup with a fresh run.
Does scanning write to my memory card?+
Your memory card is only read. Nothing is saved to it.
How do I know whether the result is complete?+
The backup holds when each camera folder and the recorder folder match their card by file name and exact byte size.