Lightroom allows you to export your photos in:
- JPEG: Joint Photographic Experts Group
- PSD: Photoshop document
- TIFF: Either “Tagged Image File Format” or “Tag Image File Format” depending on when. Now it’s only TIFF.
- DNG: Digital negative
Exporting photos as DNG file is mostly done for archiving. The exported DNG photos are the photos after all the edits done in Lightroom. The DNG format was created by Adobe, and is based on TIFF like all the other RAW formats. The DNG format allows to embedding:
- JPEG preview
- The original raw file
- All the metadata
The DNG frees you from dealing with the XMP sidecars.
Lightroom: Export DNG
Selection of the DNG format.
- Do you want the extension to be DNG upper case or dng? The reason for that is that some operating systems are case sensitive and some are not, like Windows.
- Do you want to embed the JPEG preview in the DNG photo? Normally it is embedded. The full size JPEG preview will make the DNG file larger. The JPEG preview allows any photo viewing software to read and show you the DNG photo. Many software cannot process DNG but can read the embedded JPEG preview.
- Compression: If you want you can compress the DNG file. The compression is lossless, meaning that you do not lose any quality, it will only a few more CPU cycles. Typical compressions are around 40%.
- DNG allows you to embed the original unprocessed raw file/photo inside the DNG file. This will increase the size the DNG file, but you will be able, at a later time, to extract and restore the original raw file from your camera. The only draw back is that it increases the size of the DNG file significantly.
Where to export the photo? The original folder or any other specific folder. If the file exists, what will Lightroom do? Ask you, overwrite, or rename the new file.
- Any naming scheme? The original file, whatever you want… I usually use the same naming system that I use to import the files.
- Image sizing: Is disabled.
- Metadata: In my case, it’s disabled, because I am already using DNG files. If you use other raw formats such as Canon’s CR2 or Nikon’s NEF then you will be able to decide if you want to remove your metadata, and only keep your copyrights and keywords?