Files corrupted and renamed with wrong extensions after moving within Capture One — warning and seeking help
Warning: Moving files in Capture One may corrupt your library and rename your RAW files with wrong extensions
I recently moved a large number of photos from within Capture One to an external drive and discovered serious corruption afterwards. My Sony ARW files had been renamed with incorrect extensions — including .NEF, .JPG, .TIF and .DNG — meaning Capture One and other software could no longer recognize them correctly.
The files themselves were not destroyed — the image data was intact — but the extensions were wrong. I confirmed this using the Mac terminal file command, which showed the files were genuine Sony ARW data despite having the wrong extensions. Some files were also renamed after other files in the library, which raises further concerns about whether original images were overwritten in the process.
One detail worth mentioning: at the time I was using an unpowered dongle attached to my Mac mini to connect the external drive. I don't know whether this contributed to the problem, but if an underpowered connection can cause this kind of file corruption and incorrect renaming at scale, that is extremely serious. Unpowered dongles that can silently corrupt data during file transfers should not be on the market.
I'm posting this as a warning because this could happen to anyone moving files from within Capture One, and it's not obvious until you try to open the files. If you've recently moved files and notice anything strange, check your files with the terminal before assuming everything is fine.
Steps to check your files: Open Terminal and run: file '/path/to/yourfile.NEF' If the output says manufacturer=SONY but the extension is .NEF or anything other than .ARW, your files are affected.
Has anyone else experienced this? And does anyone have suggestions on how to assess the full extent of the damage and recover files that may have been overwritten or incorrectly renamed? Any help or shared experience would be greatly appreciated.