Almost 5 years ago I wrote an article on the pros and cons of using RAW versus JPEG and why I was shooting in RAW (see RAW vs JPEG: Is Shooting RAW Format For Me?). These days the argument of using RAW versus JPEG is well… not an argument at all. Most photographers realize that shooting in RAW provides a great number of benefits and many if not all the reasons to avoid using RAW have been nullified thanks to a variety of technical innovations including larger capacity compact flash drives & hard drives, maturation of RAW converters, development of photo specific editing/management software and faster more powerful computers. Now the question that faces photographers is should I convert my RAW files to DNG?
What is DNG:
DNG (digital negative) is a public archival RAW format developed by Adobe Systems Incorporated. The intent of the DNG format is to provide a common archival standard for software developers and camera manufacturers. DNG has been integrated into a variety of software applications, beyond Adobe products such as Lightroom and Photoshop, and is currently supported as a native file by several camera manufacturers (see DNG Supporters ). Proprietary RAW formats from cameras that do not support DNG natively can be converted via Adobe’s free DNG converter application or through well known programs such as Lightroom, Photoshop, Aperture, GIMP, etc.
Pros and Cons of DNG:
- DNG files offer you the option to embed the original RAW file with in it
Note: The RAW file can be extracted via the DNG converter application
- DNG files often are smaller* in file size than the original RAW file
(* less the embedding of the original JPG or RAW file)
- DNG is a universal format addressing the issue of non-standard RAW formats between the various camera manufacturers.
Note: Adoption of the DNG standard enables files from new cameras to be immediately supported by photo editing software.
- Adobe software enables auto conversion upon importing of image files
- DNG files can have the metadata written to it versus to a separate XMP sidecar file simplifying file management
Note: This minimizes risk of XMP sidecar file loss or worse the impact of the corruption/loss of an Adobe Lightroom database)
- DNG is not a native format from Nikon or Canon, two of the largest camera manufacturers
- DNG file conversion does take extra time
- Release of new proprietary RAW formats could delay ones ability to convert RAW files to DNG until Adobe software updates are released
- There is a risk, albeit very small, of camera manufacturers no longer participating in Adobe RAW/DNG programs
- Corruption of DNG files during the conversion process
- DNG files that include the original RAW file do take up more space than the original RAW file alone.
Why I’ve Converted to Using the DNG format:
I’ll be honest upon the announcement of the the DNG format in 2004 I never saw the value in using it. DNG seemed to be an unnecessary step that would add more time to my workflow and complicate my backup process. Not to mention back in 2004 there was uncertainty as to whether the DNG standard would be widely adopted.
Earlier this year DNG has officially become a part of my digital photography workflow. Upon import of my images to Adobe Lightroom I convert all my RAW files to DNG. Conversion of my RAW files to DNG happens before anything else. Only after the conversion do I begin my post-processing and keywording. Why the change of heart toward DNG?
My acceptance of the DNG file format was one of necessity. Two things happened that forced me to rethink my workflow:
- I had a hard drive failure where I fortunately avoided catastrophic data loss (See A Happy Ending to My Drive Crash)
- I picked up a new laptop to work on when in the field and needed a solution to easily synch metadata, keywords and image adjustments to my primary Lightroom database found on my office workstation.
Both of these issues were easily addressed by adopting the DNG file format. With metadata, keywords and image adjustment being written to the DNG file it alleviated the need for complex synchronization of RAW + XMP files and/or Lightroom database files. Focusing solely on synchronizing the DNG files knocked out two birds with one stone.
Lastly if I’m ever faced with a request to provide a RAW file as part of a photo licensing or publishing request I know with a DNG file my contact/licensing info will be embedded in the file versus in a loose XMP sidecar file.
Additional Questions & Thoughts:
Is DNG conversion of RAW files something I’d recommend?
Now that I’ve had a chance to work with DNG files in my revised workflow I think the answer is a solid yes. The DNG standard continues to gain momentum and the conversion process & options are robust enough for most everyone.
Does time to complete DNG conversion take long?
Conversion of RAW files to DNG does require extra time, but if you have a relatively new computer the time needed to complete the conversion should be minimal.
Is the conversion process perfect?
Unfortunately it is not. I have had situations where DNG files were corrupted upon creation. This has been a rare occurrence, but it does happen. It’s for this reason that I do keep a temporary copy of all my RAW files until I verify that the conversion has happened with out issue. Simply repeating the conversion of the file in question is enough to remedy the situation.
Does metadata get written to the DNG file automatically in Lightroom?
No, to write metadata to the DNG files from the Lightroom library you’re working in you must select all files you’d like to modify and select “Update DNG Preview & Metadata” under the “Metadata” menu.
Do I still backup my Lightroom library now that I use DNG files?
Yes I back up my Lightroom library both to a second drive on my computer and to a USB thumb drive I store off site. I do this to preserve metadata, keywords and image adjustments to older files found in my library that have yet to undergo DNG conversion. I also do this to save time in the event I need to restore my Lightroom database if the original is ever corrupted or lost.
Adobe Digital Negative (DNG) – Adobe.com
DNG Supporters – Adobe.com
DNG vs RAW Space Savings Chart – digitalstory.com
Bridge & DNG Workflow – DAM Book by Peter Krogh
Real World Camera Raw with Adobe Photoshop CS4: Using Adobe DNG Converter – Bruce Fraser and Jeff Schewe
[tags]Photography, Software, DNG, RAW, JPEG, Adobe, Metadata[/tags]