Today’s Question: I originally imported files in Lightroom Classic CC as DNG files. I switched to importing the CR2 [original raw capture] files a few years back. When I go to the menu and choose Edit > Preferences > File Handling > File Extensions, the only options I see are dng or DNG. How do I make the change back to CR2? And what’s the difference between dng and DNG?
Tim’s Quick Answer: The filename extension (which can be upper or lower case) reflects the file type. While you can convert an original raw capture to the Adobe DNG (Digital Negative) file type, you can’t convert a DNG file to a proprietary raw capture format. Your only option would be to extract the proprietary raw capture file from the DNG if it was embedded originally, or to recover the proprietary raw capture files from a backup.
More Detail: The Adobe DNG file format was created as an alternative to the many varieties of proprietary raw capture formats created by camera manufacturers. Some cameras include the option to capture in the Adobe DNG format in place of the proprietary raw capture format. In addition, when importing photos into Lightroom Classic CC you have the option to convert your raw captures to the DNG format. To do so you select the “Copy as DNG” option (rather than the “Copy” option) when configuring the import for your new photos.
It is not possible to convert and Adobe DNG file to a proprietary raw capture format. However, if you embedded the original raw capture in the DNG file, you can use the Adobe DNG Converter application to extract that embedded raw capture. This would be done using the DNG Converter directly, outside of Lightroom.
The option to embed the original proprietary raw capture in the DNG file would need to have been selected before importing (or otherwise converting) to create DNG files from your proprietary raw captures. That option can be found on the File Handling tab of the Preferences dialog in Lightroom. Simply turn on the “Embed Original Raw File” checkbox, and when you create DNG images the original raw will be embedded as part of the file.
If you did not use the option to embed the original raw capture in the DNG files you created, the only option would be to recover from a backup copy of the original proprietary raw captures. However, if you used the “Copy to DNG” option during import, you may not have such a backup. Unless you manually copied the files yourself, the only backup of the original raw capture files would have been created if you made use of the “Make a Second Copy To” option in the Import dialog. That would cause a copy of the original raw captures from your media card to be copied to the designated location. When copying as a DNG file, the original raw capture file is not retained, so this backup option during import would provide the only other way to access the raw captures.