Cameras · Sigma exFAT photo card
Recover missing Sigma DNG files
How can I recover deleted Sigma DNG photos?
Short answer
First check whether the DNG files were deleted or only lost in a failed transfer, then leave the Sigma card unused. Scan it read-only for DNG. A header with an embedded preview does not prove that the full sensor data survived, so accept a file only when it develops at full size.
The situation
DNG originals are missing after deletion or a transfer problem.
The first thing to settle is whether the DNG files were deleted on the card or never arrived during a transfer. A stalled copy leaves the originals in place, while a deletion releases the directory entry and leaves the sensor data in unallocated blocks until new frames claim them.
01 / Diagnose
Work out what actually disappeared
Sigma cameras store DNG on an exFAT card, and a DNG carries both a small embedded preview and the full sensor payload. Those two parts sit in different regions of the file, so a candidate can show a perfectly good thumbnail while the blocks holding the image data were already handed to another file. A transfer that broke off mid-copy produces the same kind of half file on the destination.
A DNG header and embedded preview are not proof that complete sensor data survived.
Check the last known path, trash and backups without writing to the original device.
02 / Protect the source
Preserve the best recovery chance
- 1
Stop using the Sigma card at once and check the transfer destination, including any partly written copies, before you scan anything.
- 2
Note the frame numbers and the approximate shot count, so you can tell afterwards how complete the recovery actually is.
- 3
Scan the card read-only through a reader with DNG selected, and let the scan keep each candidate's full extent rather than the header alone.
- 4
Export to a second drive and immediately open a handful of files spread across the whole sequence in a RAW converter.
Do not retry the failed transfer onto the card, and do not delete the half-copied files in the hope of a clean second attempt. Writing to the source can claim the very blocks that still hold sensor data, and a half file on the destination is still evidence.
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.
File Recovery Hero recovers whole DNG files from readable exFAT cards; it does not mend one whose sensor blocks are gone, and it cannot read an APFS or HFS+ volume if the transfer target was a Mac disk. A card that fails to mount at all needs laboratory work.
04 / Verify
Check the recovered content, not just its name
Accept a file when the converter develops it at the full pixel dimensions of that Sigma body, not when the file manager shows a thumbnail. Check that the exposure data is readable and that the rendered image has no flat grey area at the bottom, which marks the point where the data ended.
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 Sigma exFAT photo card be recovered in this situation?+
The first thing to settle is whether the DNG files were deleted on the card or never arrived during a transfer. A stalled copy leaves the originals in place, while a deletion releases the directory entry and leaves the sensor data in unallocated blocks until new frames claim them. The result still depends on what remains readable on the source.
What should I avoid before scanning?+
Do not retry the failed transfer onto the card, and do not delete the half-copied files in the hope of a clean second attempt.
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?+
Accept a file when the converter develops it at the full pixel dimensions of that Sigma body, not when the file manager shows a thumbnail.