RAW vs. DNG

Written by: Tiffany Joyce

The debate on whether to import and post-process files as RAW or as DNG (Digital Negative) is almost as heated – and opinionated – as whether to shoot with Canon or Nikon. The long and short of it is, “it depends,” and “it’s up to you.” There is no “right” answer.

RAW files are digitally unprocessed image files that come straight from your camera. They have no adjustments or alterations made to them so that when you load them into your post-processing software, you have the utmost of flexibility in altering things like exposure, white balance, and the like. The RAW “recipe” varies between camera manufacturers, which means that the file formats are not universal between software brands and versions. For example, when I upgraded from my Canon Rebel XTi to my Canon 7D I also had to upgrade from Photoshop CS3 to CS5, because CS3 didn’t support the 7D’s RAW files.

The DNG file type is very similar to a RAW file in that it is an unprocessed image file that can be manipulated and altered. It is an image standard developed by Adobe and is intended to be a type of “generic” RAW file that is universally compatible regardless of the camera brand. Upon import, the RAW files that your camera took are converted into the DNG file format (so, the RAW files are still on your camera’s memory card until you format it). More software programs can read DNG file formats than proprietary RAW file formats. For instance, if my files had been imported in the DNG format instead of RAW, Photoshop CS3 would have been able to read the files from my 7D.

Many photographers choose to convert their RAW files to DNG upon import for the following reasons:

- DNG files are smaller than RAW files (by around 15%). This is because “unrecognized metadata” (such as focus points and picture control settings) is stripped from the file.
- Any changes and adjustments made to the file are written to the DNG file itself, rather than appending a “sidecar” .xmp file which contains all of the changes.
- Photographers anticipate that the DNG file format will be supported farther into the future, minimizing the risk of obsolescence and incompatibility with future programs.

Many photographers choose to use RAW for the following reasons:

- RAW files open, import, save, and edit more quickly because there is no need to convert to another file format during the process.
- RAW files contain more metadata specific to the camera and the shot itself, which is important to many photographers.
- DNG files are not compatible with some brand-specific imaging products and solutions.

It is important to note that there is no difference in image quality between a DNG and a RAW file.

Personally, I have worked with both. I tend to stick with the RAW file format because I like lots of metadata, and it’s easier for me to go back to original RAW files when I want to try multiple editing techniques on a single image. There are many schools of thought on whether to stick with RAW or import to DNG. I found a handful of articles that you might find to be helpful in making your own decision.

Helpful Resources:

- To DNG or not to DNG at Lightroom Killer Tips
- RAW vs DNG – A Practical Overview of the Differences, a video by SLR Lounge
- A primer on the Digital Negative file format by Adobe.
- Understanding Digital Raw Capture by Adobe.

Do you have an opinion on whether to use RAW or DNG? We’d love to hear your thoughts in the comments or on our Facebook Page.

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