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why use DNG?

Discussion in 'Image Processing' started by kevinparis, Jan 21, 2013.

  1. kevinparis

    kevinparis Cantankerous Scotsman

    Feb 12, 2010
    Gent, Belgium
    An issue that has come up on the very excellent... if sometimes fiesty thread

    https://www.mu-43.com/f48/mu-43-post-processing-challenge-7-a-39838/

    is that a certain kind of DNG... we are not sure quite what version yet...is not the universal future proof read anywhere format that Adobe likes to think it is.

    I have been doing digital photography for 10 years... and from the birth of DNG have not bought into the supposed advantages.

    Recently on the PP challenge thread I have twice encountered DNG images that could be neither read by a very up to date Aperture or indeed a a 7 year old version of photoshop.

    on the other hand there have been DNG files i can read happily. this doesn't sound like a universal format to me

    I shoot RAW.. i keep as native RAW... I dont trust DNG

    and not as a boast, but to keep the conversation on topic .. I have used a mac every day for 25 years, worked for apple for 9 years and helped launch Aperture in Europe by standing in front of a lot of people and actually using it



    K
     
  2. tuanies

    tuanies Mu-43 Veteran

    227
    Jun 13, 2011
    Graham, WA
    Tuan Huynh
    Because they expect you to use Lightroom to read it :)
     
  3. kevinparis

    kevinparis Cantankerous Scotsman

    Feb 12, 2010
    Gent, Belgium
    but lightroom reads raw, jpeg and tiff just fine?


    ahhh..see where you are going:)

    K
     
  4. Promit

    Promit Mu-43 All-Pro

    Jun 6, 2011
    Baltimore, MD
    Promit Roy
    It's like the web. The "standard" is the one thing guaranteed not to work universally.
     
  5. jeffg53

    jeffg53 Mu-43 Veteran

    270
    Aug 22, 2012
    Sydney, Australia
    Jeff Grant
    It may have changed but you used not be able to work on Hasselblad DNG files in C1. I assume that C1 checked the EXIF data and rejected the file. I also know that a DNG exported from Phocus doesn't contain all the corrections that you would get in a TIF. Apparently the DNG format doesn't support whatever was needed to be specified.

    I will stick to raw and live with the resulting pain.
     
    • Like Like x 1
  6. There is more than just one DNG format. If a DNG has been saved to the latest version, you won't be able to open it with outdated software. Each version of Lightroom or Photoshop will be able to read DNG file formats that were current at the time of it's release or earlier. I thought that the point was not for old software to be able to see into the future, but to reduce the likelihood of future software no longer supporting older, more obscure types of raw files.
     
    • Like Like x 4
  7. jeffg53

    jeffg53 Mu-43 Veteran

    270
    Aug 22, 2012
    Sydney, Australia
    Jeff Grant
    I thought that the idea behind DNG was to create a single format which would be readable by all apps. You just gave me another reason to avoid it. I'm glad that JPG and TIF don't work that way.
     
    • Like Like x 1
  8. Salt Peanuts

    Salt Peanuts Mu-43 Regular

    61
    May 26, 2012
    Massachusetts
    Haj
    I recently stopped using/converting to DNG in LR when it occurred to me that I may want to switch to a different RAW converter in the future. Now I wish I had kept all my original RAW files but hindsight is 20/20.
     
    • Like Like x 1
  9. kevinparis

    kevinparis Cantankerous Scotsman

    Feb 12, 2010
    Gent, Belgium
    Really ? people are deleting their original RAW files for DNG ?


    please tell me you at least ticked the option to include original RAW?


    K
     
  10. jeffg53

    jeffg53 Mu-43 Veteran

    270
    Aug 22, 2012
    Sydney, Australia
    Jeff Grant
    I feel an 'Oh duck' moment coming on.
     
  11. I think that the purpose of DNG is being confused here.

    Firstly, it is a raw format not an image format, so it shouldn't be compared to jpeg or tiff files. Like any file type, Adobe tweaks the format from time to time which is why you can't read the latest DNG type into an old piece of software. However, you can use the (free) Adobe DNG convertor and save a DNG or other type of raw file to an older DNG format which will allow it to be opened by old software (or newer non-Adobe software that hasn't been updated to read the latest DNG format). The difference is that the older DNG formats aren't as efficient in terms of file size*. In this way, you can buy the latest camera and convert it's raw files to an older DNG format that will allow you to open the file on your old software. In that sense, it provides an alternative that doesn't require you to upgrade your software.

    Personally I don't convert my raws to DNG and then delete the raw file, but before I purchased Lightroom 4 I would copy the raw files from my E-M5 and Canon G1X to DNG files so that I could edit them using an old version of Adobe Camera Raw that didn't support the newer cameras.

    * For example, older (I'm talking real old) versions of DNG didn't store images from Micro 4/3 cameras with lens correction data efficiently. The file sizes could be in the order or 50Mb for a 12 megapixel file.
     
    • Like Like x 4
  12. whatisinthebag

    whatisinthebag Mu-43 Regular

    192
    Dec 23, 2011
    Central California
    Chris
    Here some interesting points for DNG use.
    [ame=https://www.youtube.com/watch?v=XVRamaDMcX0]DNG Enhancements in Lightroom 4 - YouTube[/ame]

    Regardless of your feelings about DNG, it is a more open format than the proprietary camera manufacturers. GIMP among other support the DNG format.

    Aperture may never support DNG because it is Adobe, and the feelings between Apple and Adobe are not warm ones. Even though they both secretly love each other's equipment.

    Here's a great list of DNG supporting software that are not adobe:
    Products that support DNG in some way
     
    • Like Like x 4
  13. Salt Peanuts

    Salt Peanuts Mu-43 Regular

    61
    May 26, 2012
    Massachusetts
    Haj
    Oh I've got most of them backed up, except for some where that option wasn't checked off when I had to re-install LR and I didn't realize that for a while.
     
  14. kevinparis

    kevinparis Cantankerous Scotsman

    Feb 12, 2010
    Gent, Belgium
    aperture does support DNG... the issue is that adobe keep changing DNG,,,it is far from being an open format like tiff and jpeg

    k
     
    • Like Like x 1
  15. jloden

    jloden Mu-43 Hall of Famer

    May 15, 2012
    Hunterdon County, NJ
    Jay
    First, I'll say up front I don't use DNG, I keep everything as RAW files or edited & exported JPG files currently.

    Nic has already covered the main points... DNG is designed to be a forward compatible (not necessarily backward), open format for lossless image storage. It's a raw image format based on TIFF with a bunch of extra metadata extensions, available for anyone to implement as an open standard. The benefits & purpose of creating a new standard instead of proprietary RAW format for each camera's output are pretty basic:

    1) Digital photo archiving - it's even recommended by the Library of Congress over RAW for this purpose. See below for some of the technical reasons why. Also note that DNG supports lossless compression, so you needn't lose data versus RAW files.

    2) DNG being an open standard means it doesn't have to be reverse engineered. Older DNG files can be opened by current software and/or have new software written to work with them without legal or technical issues of proprietary formats.

    3) If camera makers implement DNG (some have, but not all) in-camera, you won't have to wait for Adobe, Apple, or whoever else to support each new camera's proprietary RAW format, since it could use a consistent DNG format across makers.

    Again, I haven't used it as a format and I'm not recommending it personally or anything, but the purpose of creating Yet Another File Format in this case actually seem pretty clear & functionally useful. I can readily understand why many folks are switching to DNG for long term lossless storage and it may be something I will consider in the future.

    Further reading: Digital Negative - Wikipedia, the free encyclopedia
     
    • Like Like x 2
  16. kevinparis

    kevinparis Cantankerous Scotsman

    Feb 12, 2010
    Gent, Belgium
    seriously.. you posted that video as a positive for DNG?... I am frickin amazed that adobe let that out the door.

    and I am sorry... but using Gimp as an endorsement really does not cut it.. the whole pixel editing paradigm of photoshop/gimp died 7 years ago.

    real time non destructive raw editing that both Aperture and Lightroom offer is the the way to go

    K
     
  17. Just Jim

    Just Jim Mu-43 Top Veteran

    941
    Oct 20, 2011
    Will an 8 bit jpeg exist in 5-10 years? It's a dated format, and it will die as it currently exists. All images now in JPEG will be stuck that way regardless of color gamut and bit depth advances. At the worst, they won't even be readable. Most likely you'll have to deal with open source readers that will be shady and misfiring every time new OS's come out to read jpegs. At best Adobe and the like may keep up with them for some archival purposes, and expect the support to be weak. Specific raw files the outlook is even bleaker, whose going to keep up with raw readers once all companies not named Canon or Nikon are done with imaging devices, and even Canon/Nikon are only sitting a bit prettier just due to sheer volume. Adobe isn't promising so much as they are warning that they will not support specific raws forever. Afterall, they are a business, not a charity.
     
  18. Tell a lie; I do still use DNG files for something. My Samsumg NX200 saves uncompressed raw files at approx 30-40Mb a pop (it was about 50Mb prior to a firmware update!). When I convert them to DNG the file size goes down to less than 20Mb (using the lossless compression, not the lossy compression mentioned in the video that whatisinthebag linked to). In this case I do delete the original raw file.
     
  19. jeffg53

    jeffg53 Mu-43 Veteran

    270
    Aug 22, 2012
    Sydney, Australia
    Jeff Grant
    How many billion TIF and JPG files do you think are in stock agencies etc around the world. They may go away but not soon. I'll worry about converting my raw files when I have to not because Adobe would like me to. While I use a Hasselblad, the best file is TIF not DNG so it's a no-brainer for me.
     
  20. kevinparis

    kevinparis Cantankerous Scotsman

    Feb 12, 2010
    Gent, Belgium
    1) wouldn't trust any federal us organisation to be unbiased....seen enough Jon Stewart to realise that US ... like all politics can be bought

    2) Issue is that older software cant read newer files... even if they were taken on older camera... smells like an adobe lock in

    3) can only think of Leica and maybe Hasselblad who have gone the native DNG route...wonder why?

    K