Converting Digital Camera Raw Files to the Dng Format using Adobe Photoshop Lightroom
I am a big fan of the Dng raw file format. Dng files hold all of their metadata internally without the need for separate external .xmp sidecar files. I believe that is a huge advantage over the proprietary, camera-brand specific, raw files that my digital camera creates. In my workflow smarter files are worth the extra step that it takes to turn a camera brand specific raw file into a Dng raw file. Adobe Photoshop Lightroom makes this conversion, this re-wrapping of the raw sensor data, super easy.
In Lightroom, we can shift most any brand of raw file into the Dng wrapper at the front-door as we empty our memory card.
Converts raw files to dng on import
We can also convert raw files that are already in our Lightroom catalog over to Dng using the Library > Convert to Dng feature.
Converts raw files that are in the Lightroom Catalog to Dng
Finally, we can create a new copy of a raw file outside of Lightroom using the File > Export dialog and selecting the Dng file format.
Converts a copy of a raw file outside of Lightroom to Dng
Watch this tutorial video for more on the advantages of Dng and on how easy it is to use this advanced file format with Lightroom.
Converting digital camera raw files to DNG using Lightroom from David Marx on Vimeo.
Click here for more information on the advantages of the Dng file format.
Filed Under: Exporting Images • Importing Images • Workflow
About the Author: David’s sports and landscape images are often used on the web and in outdoor sports publications. He has an extensive knowledge of digital photography and is an Adobe Certified Expert in Photoshop and Adobe Photoshop Lightroom. David is a talented instructor and his entertaining teaching style works for students of all skill levels.
In 2009, David Marx led digital photography programs for the 
When you import in Lightroom, do you keep a copy of the original raw file somewhere, or are you depending on the dng files for everything?
Dear Dick F,
This is a personal choice. In my workflow, I do not store a copy of the original raw file in its proprietary (camera branded) file format anywhere. This makes life easier for me, but not all professionals will agree on this one.
If you only keep the dng file then you have cut yourself off from software that doesn’t work with dng. This means that my dng raw files will not work with the Canon Digital Photo Pro, Nikon NEF / Bibble, etc. This could be a big negative for some folks.
Personally, I am thrilled with Lightroom and ACR for all of my raw conversion needs. I don’t feel like I need any of these other programs, but again not everyone will agree.
David
Dick,
I’ll chime in on this one and say that I agree with David. I don’t ever plan on needing to go back to the “original” raw out of the camera, so I discard it after creating a DNG version.
There’s no right or wrong, though. You’ll find many different (heated) opinions on this.
-Scott
Yeah always.
ONLY because it produces a smaller file than my Sony A350’s RAWs (about 1MB smaller)
When I first got my Nikon D90 I couldn’t read my RAW files in any program for several months because it wasn’t yet supported.
Annoying and scary.
I convert everything to DNG now and delete original raw files… The future is much more likely to support the large universal standard of DNG than a camera specific Nikon D90 RAW .nef file.
Perhaps it’s because I’m not a pro, but I always use the original RAW files. Although I use Lightroom to manage my library, the camera vendor’s supplied viewing software provides additional EXIF information that that is useful in determining why a shot was spectacular – or not. For example, more details can be found in the RAW file regarding AF, AE, image stabilization, and flash information.
Maybe I’m crazy but I trust Adobe and don’t even bother with Nikon’s CaptureNX software. I exclusively use Lightroom and convert to DNG on import and discard the original RAW/NEF files.
One big negative for me with DNG is that the XMP data is written into the file rather than existing as a sidecar.
Here’s why: every time I change anything that gets written to XMP, that means the whole file has changed. And it slows my regular backups to network locations down tremendously. There is quite a difference between backing up a few hundred kilobytes in an XMP sidecar vs. 25MB in a 5D MkII DNG file.
I don’t have any problem keeping the XMP files sync’d with the originals: I don’t rename the files in the filesystem (I don’t care what they’re named) so that probably helps a lot.
I tried using DNGs for a while and I still get hit by this when I tweak my keyword system (it’s a forever-evolving system) and keywords get updated in those DNGs from that time.
DNG all the way for me. Although, I do have Lightroom keep a copy of the original RAW files in a separate folder I have never had to go back to those files. Knowing I have that backup lets me be extra aggressive when rejecting photos out of my catalog (I tell LR to delete them off the filesystem as well).
Kudos, Mike, for being aggressive in deleting those rejects. A good photographer not only takes good photos, but keeps his or her collection of images pared down to only the best.
-Scott
PS-I’m not that great at it yet. I could use some work on narrowing down my library!
So when you make any changes to the metadata, it is updated in the DNG file format? This all seems much more simple and organized than the CR2 format. I have lost edits because of sidecars not getting written or not exporting properly. I am nearly convinced this is the best route to go…
Bettie,
Yes, as long as the Automatically Write Changes to XMP checkbox is checked (or you save changes to your files), the metadata is written to the DNG file. No more sidecar files.
For me, it’s certainly the best solution.
-Scott
I don’t agree that you should only keep your best photos. I love looking at my bad photos because I can see how I’ve grown and / or what didn’t work. Also, if I ever want to create a book on how to photograph, it’s nice to have examples of what didn’t work, or progression of how the shoot went. In addition, some photo’s I take of my dogs, family, vacation may not be works of art, but have great memories.
I have read of photographers having another catalog that is just their best takes. That may be a good option so you don’t have the outtakes cluttering up the final picks in a catalog.
I do of course edit out the really bad, totally blurred, over/under exposed, etc.
That’s my 2 cents.
I have a NIkon D80 and for the last six months when importing images in NEF format to my Mac through Lightroom 2.x or Finder after around 10% have been imported the computer freezes indefinitely and would not allow a forced quit. That corrupted the Lightroom database and meant retrieving the backup. The work around was to only import a very small number at a time – tedious.
This morning, before calling Apple again(!) I tried converting to DNG on import and bingo, no problem. Has anybody else experienced this problem on a Mac with NEF files? I think I’ll stick to DNG in the meantime though!
@Leslie:
Thanks for you comment. As a teacher, I keep a lot of my mistakes, as well. However, I see students time and again who have unmanageable catalogs due to the sheer volume of mediocre images. One of the most frequent mistakes made by amateurs when showing their work is that they flip through image after image of bad shots muttering the mantra “Ok, there’s a good one coming up here somewhere…”
Anyone who’s sat through a slideshow of someone’s vacation pics can attest to that!
@Andrew:
I’ve not run into that issue before. Were you importing straight from the camera or were you using a card reader? Although an import with the camera plugged directly into the computer should work, I always recommend using a memory card reader. They are typically much faster and can reduce the (already low) likelihood of damage to your camera from a USB power issue.
-Scott
Scott, I’ve been importing directly from the camera. I assumed the problem was not related to this as transferring NEF files around in Finder also causes the same problem to arise. As I say, now that conversion to DNG format seems to have resolved the issue I’ll stick to that format and ditch the NEF files once converted. That said, I’ve heard from other sources that a card reader is more reliable than the a direct import from the camera and I think I’ll use one from now on to be on the safe side.
Thanks,
Andrew
Interesting issue, Andrew. If you’re experiencing the problem from the Finder as well as directly from the camera, then, you’re right, I’m sure it’s not the direct camera import that’s the issue.
I prefer DNG anyway, but I know it’s frustrating when things don’t work the way they should.
-Scott
Micheal W Gray published this excellent article on DNG conversion recently on the X-Equals blog.
Grant Gunderson, one of my favorite photo editors / publisher, is now accepting “Dng raw files” with “meaningful metadata” only for consideration in his magazine The Ski Journal. I believe that we will soon see similar rules from all of the topflight publishers. Click here to see The Ski Journal’s complete submission guidelines.
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David Marx
thank u for this great explanation on dng files. my question is if the dng already contain all the metadata, do we still need to import as a catalog? can we just convert to dng?
Dear Lisa,
I am not sure that I understand your question. This tutorial is all about how to shift your raw files into the dng format within Lightroom. You would only use the “Import as Catalog” feature if you were combining one catalog into another. Why and where are you using this option in your routine?
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David
thank u David,
what i understand here is Catalog= metadata, DNG= metadata+photo. so if we have both metadata and photo in DNG file, why we need Catalog to record the metadata? sorry to confused u :d
Dear Lisa,
This is confusing stuff and you are on the right track. Metadata is any textual information added to a digital image.
By converting to the Dng file format this textual information– your copyright for example–can be stored along with the raw sensor data inside of each file. Raw files in proprietary, meaning camera brand specific, formats cannot hold this sort of text internally. Since they can’t store the info internally these files need a sidecar xmp file, think of it as a post-it note, to hold important information.
This internal vs. external metadata storage is a property of the file’s themselves regardless of what image management software you use. What makes Lightroom special is that it builds a searchable index for your photography.
For every file– meaning every photo–that is added into your index Lightroom creates an “index card.” Each “index card” records the file’s name, it’s location on your hard drive, all of it’s metadata, and a couple of thumbnail-sized copies of the image.
Searches in Lightroom produce almost instantaneous results because the catalog keeps its own records about your images. (See Lightroom vs. Adobe Bridge for more details.) Not only does the catalog produce instant search results but it can also store information that is not part of the file’s metadata. Features like the pick / reject flags, collections, and virtual copies are all stored only at the catalog level. There in’t a metadata field for the name of a collection or for a virtual copy.
What I am trying to say is that we need the catalog for two reasons: a, fast searches even if the file’s themselves are offline and b: to store features of the program that cannot be written into a file’s metadata.
I hope this helps,
David
thank u very much, Dave!