Is switching to DNG worthwhile?

I'm aware of the difference between RAW and DNG file formats. The RAW format is proprietary to the camera manufacturer while DNG is an open standard. DNG files can be compressed without loss of detail, and can also include the photo metadata within. Both can be edited in Photoshop.

Would DNG be considered widely used today? I have a library of photos in NEF (Nikon D50) format that I have been contemplating whether to convert.

Answers 8

  • Whatever you do, do not throw away your original RAW files. DNG is not a replacement for them. Perhaps your workflow requires you to convert into DNG's, but for the love of god do not throw away the originals.

    If you do, then one day you will find that you will want to use a piece of software that doesn't support the DNG format as input.


  • agreed on not throwing away the original raw; Many import systems allow you to embed the RAW inside the DNG, so it's there if you need it; I personally do that on all of my images.

    I use DNG primarily because that format includes the metadata sidecar as part of the DNG, where for RAW files, the metadata sidecar is generally a separate file. Bundling this all into one file simplifies workflow and makes it difficult to separate the two or lose the metadata, making housekeeping easier and reducing the risk of data loss. That alone made me decide to use DNG. It's convenient and if I ever need to unpack it, there are tools that can do it for me.


  • Think this way: maybe in the near future Capture NX may have a nice interface. You start using it but all your original NEF files are gone.

    To my acknowledge Capture NX is one of the best sharpener for NEF files. Don't throw away your NEF files.

    I was in the same situation as you. I converted all my NEFs to DNG. You know, DNG is "universal", smaller files etc. Big mistake. I wanted to edit some files in Capture NX but I couldn't because they were DNGs. I never converted a single NEF to DNG again.

    And do backups of your files. Multiple backups.


  • If you're happy throwing away the original RAW files then you can save a little disk space. I've converted CRW (Canon RAW) to DNG and I typically end up with files about 20% smaller with all the information there.

    Of course disk space is cheap, and Canon and Nikon RAW formats are likely to be supported for a long time to come.

    And Ricoh is another camera manufacturer who supports DNG - though that still leaves it fairly short of being widely supported by camera manufacturers. Though I would assume all major software packages should support DNG.


  • Is DNG widely used? Not really. My Pentax K200D supported it, but not very well. Leica supports it in their S2.

    NEF is very common (because Nikon is huge), enough so that I'm not worried about it going away. There is open-source software that can interpret current NEFs, so if (for example) Nikon disappeared tomorrow and took away all their software and specs and forbade third parties from creating NEF software, you could still get into the files.

    I wouldn't bother converting preemptively.


  • It depends on what software you use to store/catalogue your photos. For example Lightroom understands NEF, and I'm perfectly fine with using NEF and not DNG.


  • While Diskspace is cheap, RAW files continue to grow as well. My take: Converting to .DNG is not a bad idea at all. Why, because you should have a backup of you images anyways, so why not have a .DNG as a backup that does conserve some space at the same time. I would like to think that .DNG will not go away. It is such a common sense, no-brainer with respect to uniformity across software editors. Over time, if there are competing "open source" file formats, then conversion software will also follow that can convert .DNG to a new format.

    Why it hasn't gained widespread acceptance is attributed to the proprietary attitudes of camera manufacturer's and the software they hope to sell to work with and view their "special" formats. I have used many Canon cameras and find that there are many Canon RAW file extensions such as .CR2, .CRW, and some software will not accept both formats, especially with respect to viewers.


  • There's also an issue with software freedom:
    while DNG is open, it's also patented and non-free, and it might be the reason why many people are reluctant to spend time and resources for it beyond the basics. As a result, DNG(output) is mostly supported in proprietary software, and free software usually only has minimal or even read only DNG support. So if you decide to routinely convert stuff to (losslessly compressed) DNG and later decide to stop using proprietary software, you'll have an unpleasant surprise because you might be unable to continue doing that.

    Another possible issue:

    Some photographic competitions do not accept converted files, and some do not accept DNG

    (source)

    Both issues can be sidestepped by keeping original versions too, but then the photos will take twice as much disk space.


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