Skip to main content
B
BackDoorHippie
Participating Frequently
June 8, 2018
Question

DNG Files marked as Modified on Import

  • June 8, 2018
  • 2 replies
  • 407 views

I am a Raw shooter and have been for ages. I shoot Nikon and do not convert to DNG since I need to save "unedited and unmodified Raw files" for certain contests that I enter. When I import them into Lightroom I add my copyright information which gets stored with the file in the Lr catalog as expected, maintaining the purity of the original Raw file.

I recently purchased a drone which creates DNG files directly. Imagine my surprise when I found that all these files are modified as a part of the Lr import process (the file modified date is changed)!! I can only assume it is the application of the copyright information (something I unfortunately cannot do in-camera with the drone as I could with the Nikon) which begs the question, "Why is it that Lr chooses to modify the file instead of storing it in the catalog like it does for every other type of Raw file?

On top of that I'm here asking if I've simply missed something in the Preferences, and is it possible to import without modifying the DNG file, storing any EXIF extensions in the catalog as with the Nikon NEF and Sony ARW files I've been importing unscathed for years?

My only option is to manually preserve a second copy of all my imported data, which I probably cannot do with Lr's option to back them up to a second source since I can only assume the same modifications would be applied. Lightroom has always been touted as "non-destructive" so it just baffles me that this is how it handles DNG files by default.

    This topic has been closed for replies.

    2 replies

    johnrellis
    johnrellis
    Legend
    June 8, 2018

    I recently purchased a drone which creates DNG files directly. Imagine my surprise when I found that all these files are modified as a part of the Lr import process (the file modified date is changed)!! I can only assume it is the application of the copyright information (something I unfortunately cannot do in-camera with the drone as I could with the Nikon) which begs the question, "Why is it that Lr chooses to modify the file instead of storing it in the catalog like it does for every other type of Raw file?

    The file system's modified date (the date visible in Mac Finder or Windows File Explorer) can get changed on import in a couple of ways:

    - You have the option Catalog Settings > Metadata > Automatically Write Changes Into XMP checked. This will automatically write back any changes to metadata, including copyright, back to the photo file. For DNGs, the XMP metadata is stored inside the photo file, so you'll see the file's modification date change. For manufacturer's proprietary raw files, e.g. NEFs, the metadata will be written back to an .xmp sidecar file, so the NEF's modification date won't change.

    - Depending on the import workflow used and the platform , the imported file's modification date could change merely as the result of copying the file.

    If you want to discuss this further, we'll need much more detail, including exactly where you're viewing the modification date(s) (the program, the field name).  There are many date fields in files and in photo metadata, and it's easy to confuse them.

    dj_paige
    dj_paige
    Legend
    June 8, 2018

    Lightroom never modifies the image portion of your data. NEVER. Not at import, not at any other time. That makes it non-destructive, with reference to the image portion of your data. LR has never been (and is not now) non-destructive with regards to metadata, certain metadata can be change upon request.

    If the "modified date" is changed, could it be that the camera in your drone is set to the wrong time? I am not aware of any part of the import process that would change the times in the file.

    Furthermore, are you seeing this wrong "modified date" in Lightroom, or in your operating system? Lightroom has no control over what is shown in your operating system, and it may be showing the time the file was converted to DNG, but the file itself should still contain the capture time.

    In other words, do more investigation about what is actually happening, there are plausible explanations for all of this that may or may not include Lightroom doing something.

    B
    BackDoorHippieAuthor
    Participating Frequently
    June 8, 2018

    Yeah, that's always been my assumption in my 7 years working with it, so I'm still digging to see if I may be misinterpreting some things - I'm just not sure yet.

    Where I first saw this is when I opened the raw image into Photoshop and looked at File Info the XMP modified date shows the time of opening and not the creation time, even when I do no modifications or applications on import. That's where I got the idea that it was modifying something because I had never seen that on other files, so I opened a Nikon Raw file and sure enough it did it on that as well, so I'm guessing this is all in the building of the new file and not something that was changed on the Raw file, even if the filename still shows the raw file extension.

    The thing that is throwing me off is that when I look at the EXIF data in Lr before opening it shows the Metadata Status as "Has Been Changed", which again, it does for all files that have had the copyright info appended, but it was the combination of the two that served to confuse me.

    I downloaded an EXIF utility and opened the DNG file post-import and there's nothing showing within the reader that points to any modifications or alterations, so I'm probably completely off on this - it's been one of those mornings.

    Terms & ConditionsAccessibility statement
    Using the community Terms of use Privacy Cookie preferences Do not sell or share my personal information ad choicesAdChoices