DNG vs RAW

Should you use DNG or RAW format? This is one of the most important questions that you as a photographer need to ask yourself, because it will definitely affect your digital photography workflow. Every photographer has their own say on whether to use DNG or RAW, but it is important to know the key differences between the two, along with their advantages and disadvantages. In this article, I will provide as much information as I can about both formats, in addition to my opinion and workflow. If you are looking for more information about how RAW images compare to JPEG images, then please read my “RAW vs JPEG” article.

1) What is RAW?

RAW images, also known as “digital negatives” are truly “raw”, meaning they are almost unprocessed data coming directly from the camera sensor. Unlike JPEG files that can be easily opened, viewed and printed by most image-viewing/editing programs, RAW is a proprietary format that is tied to the camera manufacturer and sensor, and therefore is not supported by all software products. RAW files preserve the most amount of information about an image and generally contain more colors and dynamic range than other formats.


1.1) Advantages of RAW format

  1. RAW files contain full JPEG Previews that were processed by the camera, using the camera settings you chose when you shot the image.
  2. In addition to basic exposure information, RAW files also store other camera-specific data such as focus point, picture controls, etc.
  3. RAW files are fully supported by their manufacturers and therefore work with camera-specific software packages such as Nikon Capture NX.

1.2) Disadvantages of RAW format

  1. Not all software packages can open RAW files. If you have a brand new camera that just got released, you might need to wait for a while for software companies to catch up and update their software so that your RAW files could be opened and worked on, even on the most popular image-editing products such as Lightroom.
  2. Because RAW files cannot be modified by third party software, your settings will have to be stored in a separate sidecar (XMP) file, which means more storage and tougher file management.

2) What is DNG?

DNG is also considered to be a RAW image file. It is Adobe’s proprietary image standard that was created to store image data in a generic, highly-compatible format, unlike RAW files that have specific formats based on manufacturer and camera type. Although DNG was invented by Adobe and is supported in all Adobe applications, there are other companies like Leica and Hasselblad that adopted this standard and use it in their cameras as their native RAW file format.

2.1) What are the advantages of DNG format?

  1. No need to be worried about proprietary camera RAW formats – once a RAW file in converted to DNG, it will work with any software that can read the DNG format.
  2. DNG files are generally smaller than RAW files and can be made even smaller if minimal or no JPEG Preview is stored within the file.
  3. Changes to images can be written directly into DNG files without having to create separate sidecar XMP files to store this data. This simplifies file management.
  4. DNG files are capable of storing full original RAW files and these RAW files can be later be manually extracted, if needed.
  5. Adobe provides many ways to automatically convert RAW images to DNG format in such programs as Lightroom.
  6. Adobe continues to work on the DNG format, enhancing it year after year and adding more functionality and features.

2.1) What are the disadvantages of DNG format?

  1. Conversion from RAW to DNG takes extra time during the import process.
  2. DNG does not work with all manufacturer image-processing programs. For example, it doesn’t work with Nikon’s Capture NX product.
  3. DNG strips out some of the unrecognized meta data (such as Active D-Lighting and Picture Control) from RAW files, making it impossible to retrieve this data from DNG in the future.
  4. Because all changes are written into the DNG file, you would have to back up the entire DNG file every time you make changes to it.

3) Should you use DNG or RAW?

I personally prefer to use DNG for the following three reasons:

  1. Compatibility – it doesn’t matter what camera I use today or tomorrow, my files are preserved in one highly-compatible format that is here to stay.
  2. Simplicity – all changes are written into the same file and I do not have to worry about having one separate file per image just to store my post-processing settings.
  3. Size – that 15-20% of extra space does make a difference when you have tens of thousands of pictures. Why should I waste space by storing information in RAW files that I do not need?

Sure, it does take more processing power and time to work with DNG images compared to RAW, but the above advantages far outweigh the problems with RAW for me. I do not use Capture NX and within the last two years, I haven’t had a need to go back to my original RAW files. My backup process is actually simpler and smoother now, because I do not have to worry about selecting only sidecar files for backup – I just backup whatever photos I work on.

As far as whether to preserve or not to preserve the original RAW/NEF files, I personally keep my RAW files until I back up my photos to at least two separate hard drives. Once I am absolutely positive that everything is fully backed up, only then do I purge my old NEF files to save some space.

Please let me know if you have any questions or feedback in the comments section below.

Comments

  1. 1
    ) Prem
    February 9, 2010 at 11:56 am

    Hi Nasim,

    Thank you for creating this wonderful web site with Lola and contributing and sharing your knowledge of photography. I am amazed at the quality of your pictures despite reading that you only took up DSLR photography in 2007! It encourages me to keep working at my own attempts at photography. Although I’ve been enjoying it as a pastime for many, many years, I have only recently invested in a DSLR. Just as I was looking into the Nikon 300s, the Canon 7D came out and, as difficult as it was, went with it instead because of its features including superb HD video, with the approval of a Nikon user friend of mine. I’ve invested in Canon’s L lenses and keep working at improving my shots.

    In reading your articles, I’m drawn to your web site not only because of the wealth of information, but because of what I perceive as genuine warmth. Please keep up the great work as I’m sure more and more people will be drawn to it and learn from it.

    Prem

    • February 9, 2010 at 4:02 pm

      Prem, thank you so much for your feedback, we truly need it here :) I get encouraged by a lot of good comments from our visitors and want to write more and more every day! I wish I had a little more time though, since work consumes me almost completely.

      The Canon 7D is a superb camera and I have seen a lot of proud owners of this camera. Canon did a remarkable job with this camera and the video on the 7D is simply stunning.

      Good luck in your photography and if you have any questions, please let me know and I will do my best to help you out!

      Sincerely,
      Nasim

  2. 3
    ) John Berry
    February 15, 2010 at 3:03 pm

    Thanks for taking the time to detail the pros and cons of raw. I had pretty much decided to go with raw but your informative article has clinched the deal.

    • February 15, 2010 at 3:05 pm

      John, you are most welcome! Please let me know if you have any other questions :)

      • 46
        ) Dr. Peter Hampel
        May 17, 2012 at 11:14 am

        We work with fluorescent dyes and face a simple problem:
        We like to digitize fluorescent dye blots to come to measurment data (e.g. integration of area, perimeter etc.) Our canon EOS 60D delivers CR2 RAW files and the back ground has anun predictable structure

        Taking two photographs, one (1) with structured back ground only and one with structured background and visible light flurescent blot (2) Subtracting 2 less 1 ought to result the “cleared” visible light flurescent blot. Fine, but how to come to digital data ?

        Can you advise how to come to a RAW file conversion (Canon EOS 60D) into a matrix like
        Pixel x / y containing Green (some data) / Blue (some data) / Red (some data) ????

        Thank you for your help in advance

        Peter

  3. 5
    ) Bob Shank
    March 12, 2010 at 11:34 pm

    You lay out very good details on this dilemma. I have been tossing and turning over this decision and have actually gone back and forth over the last year, never seeming quite informed enough to make the decision once and for all. I do like the fact that DNGs do not use a sidecar file. However, do you know if converting to DNG does anything to degrade the image in any way (color accuracy, etc.)? I, too, am a devoted Nikon shooter and just don’t want to lose any quality. However, thanks to your informative article I am very, very close to using the DNG format exclusively. Thanks!

    • March 18, 2010 at 12:08 am

      Bob, no, DNG does not degrade image quality in any way – it is still a RAW file.

      • 7
        ) Bob Shank
        March 19, 2010 at 8:42 pm

        Thanks! I appreciate your response and the confirmation that converting to DNG does not degrade image quality. I think I am about to make the move to DNG!

        • March 19, 2010 at 9:24 pm

          Bob, you are most welcome! Let me know if you have any other questions.

      • 37
        ) Phil Wells
        November 17, 2011 at 12:27 am

        Nasim,

        Thanks for the well written articles. I have had a camera of some sort since I was 5 and am now 56 but Only got my first DSLR (Nikon D5000) in early 2010. I am no pro but people say I have a good eye for composition and I know what I like when I see it though I often don’t know what to do to improve things I don’t like.

        After getting overwhelmed by the number of pix I am collecting I settled on Lightroom 3 and it was the, apparently, ubiquitous dilemma of DNG vs RAW that brought me here. You said to Bob that DNG doesn’t degrade image quality but in the article you also say that it makes some info, like Active-D lighting, no longer available to the user. To me this says that it degrades the ability to modify the RAW file.

        How important are things like this to someone who isn’t making a living at this nor takes pix every week but is moderately picky as to how things look?

        Best Wishes,

        Phil

  4. 9
    ) Hikamata Kapatsa
    April 15, 2010 at 6:27 am

    Hi Nasim
    I must agree that it is encouraging to know that u really started out only in 2007! this is a great site and a wealth of information (i learn something new on every page i open!) Thanks for sharing!

    I am new to DSLR’s (Nikon D3000) and begining to experiment with RAW. Only problem is i can’t open NEF file in PS-CS4, Lightroom2.2 or PSE7 ? Camera came with veiw nx but its really slow and all along my JPEG edits have been done in PSE7. I have, however, found that with i can convert NEF files to DNG with DNG converter that i downloaded, i can then edit them as RAW files in my Adobe applications! Question: Is there a dis advantage to this workflow ie NEF to DNG to JPEG? am i losing something? Is there a better way?

    • April 17, 2010 at 3:06 am

      Hikamata, thanks for stopping by and dropping a comment!

      In order to open NEF files in Photoshop CS4, you need to update your camera RAW to the latest version. Here is where you can download it. Once you install the latest version, both Lightroom and Photoshop will be able to open and process the files.

      In terms of DNG, I convert all of my NEF files to DNG for future compatibility and smaller size. You do not lose any quality, because DNG is also a RAW file format. So yes, the workflow would be NEF->DNG->JPEG.

      Hope this helps.

  5. 11
    ) rafi
    September 25, 2010 at 10:00 pm

    Dear Nasim

    Wonderful article. You’ve convinced me to use DNG. However, could you point me in the direction where I can download a dng image as an example? I wanted to use photoshop dng converter to open a dng file.

    Please send me a link to a few images in dng format.

    Thank you.

    Rafi

    • October 4, 2010 at 1:51 pm

      Rafi, not sure where you can find DNG images on the Internet, since they occupy too much space. You can convert any of your images to DNG format by using a DNG converter from Adobe.

      Also, why don’t you use Lightroom to open DNG files instead of Photoshop?

  6. 13
    ) chuck king
    November 15, 2010 at 10:51 pm

    Love your article…I have a question that no seems to be able to answer for me…They dance around the answer, or lack of….When I shoot in raw, the wb, saturation, sharpness etc. is not supposed to influence the photo…But it does, as you said a raw file contains a jpeg preview that the camera settings
    influenced…This does not make sense to me…All I want to view is the “actual” raw image…no jpeg preview, no tags, nothing…just the image, like a true film negative….I tried a test using all the different wb’s in the camera, and of course they were all different…I hope I am saying this correctly…I just want to see the real raw file…Do you know if this is possible? What camera settings to use in raw, etc…If it was a truely raw photo like everyone says, then why can’t I see it? Please help if can, Thanks again for your writings, chuck king

    • November 15, 2010 at 11:42 pm

      Chuck, what software do you use to view your RAW images? When you view RAW files using regular photo viewing applications, they will only show you the embedded JPEG file. In order for you to be able to see the actual RAW file, you would need to open the RAW image in Adobe Photoshop or Lightroom and then apply your own settings to those files. If you do not want any settings applied, simply right-click the image and then go to Develop->Reset, which should reset all settings to their defaults.

    • 34
      ) Gary
      October 14, 2011 at 10:43 am

      For those of us old enough to remember film, it makes a good comparison.

      A RAW file is like film — and the human eye one cannot see the image on film. Unprocessed film is just an even-colored blank expanse to the human eye.

      The film had to be processed into a negative or slide before anyone could see the image. And the results varied depending on how the film was processed. We varied the time, temperature, agitation and chemical composition to achieve different results.

      With RAW files the processing is done with software. Better than film, you can process RAW files working in the light and reprocess the files again and again until you get the results you love. Yet like film, you cannot see a thing until it’s processed.

  7. 15
    ) Daniele
    November 18, 2010 at 6:02 am

    Thank you very much for the insight, I’ve recently started using RAW full time (I used to go JPEG most of the time, reserving RAW for “complex” shots only) and I’m in the process of defining a better workflow. Your post shed additoinal light on DNG, and I think I may have made up my mind at this point. I have a doubt, though: how would I cancel any changes I made to the DNG in Adobe Camera Raw? I’m especially confused about cropping: what if I want to go back?
    Thank you very much!

    • November 18, 2010 at 3:27 pm

      You are most welcome Daniele!

      I also have a tutorial on “how to organize photos in Lightroom“, which you might find helpful. In terms of canceling your changes in Lightroom/Photoshop – DNG, just like RAW is a non-destructive format, which means that whatever changes you make can be simply reset. In Lightroom, you can right click an image and go to Develop->Reset, which will reset everything to defaults. You can revert back the changes in Adobe Camera RAW the same way…

      • 17
        ) Daniele
        November 18, 2010 at 3:30 pm

        Thank you very much. :) I had a few issues because right clicking in ACR only shows a zoom menu, but I discovered that clicking and holding the crop tool shows a little menu that allows to reset any crops and rotations applied. As for the rest, it’s easily reset by accessing the picture menu and choosing the appropriate item. I can’t be more precise because I’m on a machine without ACR, but once again thank you for the article and for the kind reply. DNG is the way to go. Now I just need to find some place that sells cheap CF cards. :D

        • November 18, 2010 at 3:56 pm

          Danielle, I personally moved my workflow to Lightroom 3 and I don’t bother with ACR anymore. It is just too darn slow for processing hundreds of images ;-)

          • 19
            ) Daniele
            November 18, 2010 at 3:58 pm

            Oh, I’m very critical of my work, I’ll eventually only actually process a handful photos. For the others, if I need to keep them, I created an action that just runs ACR with the default parameters that I run through the ‘batch’ function of Photoshop. I start it up, and go make some tea. :)

            PS: it’s Daniele with one L; I’m an Italian male. :p

            • November 18, 2010 at 4:01 pm

              Ooops, sorry about spelling your name wrong (I did it right the first time!)

  8. December 9, 2010 at 11:57 am

    Thank you for setting up this page.

    You have solved a problem I have had for a while now.

    Its DNG all the way!!!!!!

    Thanks for all your good advice.

  9. 23
    ) Merlin
    January 2, 2011 at 10:23 am

    Good article on the use of DNG files. I use DNG files all the time. When I read this article and found out where you said that the dng files are smaller than the raw files I went to check on my camera. I use the Pentax K20D. In this camera you can specify whether you use the Pentax raw file or the dng for taking your photos. I took some test shots this morning and found that the dng file is about 2x the size of the Pentax raw files. The K20D is a 14.6 megapixel camera. The photos I took this morning were RAW 11.7mb and the DNG was 22.8mb. The DNG was twice as large as the Pentax PEF file. Why might that be? That being the case I may switch back to using the PEF format.

    • January 6, 2011 at 11:38 pm

      Merlin, DNG is not going to be smaller if you choose it as a default format on your camera, because most likely your camera is embedding the original RAW file into the DNG file as well. Shoot in RAW and then convert your images to DNG in Lightroom and you will save some space.

  10. January 30, 2011 at 4:28 pm

    I’me new to DNG conversion and open to improvements. Please help me with my problem comparing before/after size. With Lr3 conversion, I notice that with (Canon 5D MII CR2) files seem to double in size rather than get smaller by 15-20%.

    is there something i am doing incorrectly?

    Marc B

    • February 25, 2011 at 5:24 pm

      Marc, you probably have your JPEG preview file set to Large and you are probably embedding the original CR2 file into DNG, which would make it double in size. Make sure that you are not embedding the original RAW file into DNG – check your Lightroom options.

  11. 26
    ) Anon
    February 24, 2011 at 7:44 am

    Nice article. However, please not that DNG is an open format. This is the one and only reason why the DNG format is expected to survive for a very long time.
    [reference: http://en.wikipedia.org/wiki/Digital_Negative_(file_format) ]

  12. 29
    ) Eduardo Duarte
    April 17, 2011 at 6:25 pm

    Hello Nasim
    I noticed that when I export and covert a DNG to JPG the file gets reduced to 2.5MB. Thats going to affect the quality and size when I’m ready to print the image? . Raw file are larger when you convert them to JPG’s. Cna you clarify that for me thank you very much!

  13. 30
    ) Myra Barnes
    June 15, 2011 at 8:19 pm

    Hello, I have found your posts SO helpful! But I still have a dilemma. I have the Canon 60D, LR3, and CS5. I recently did a shoot for the first time using RAW+JPEG format. Now, I cannot import these photos into LR3 so that I can fix the white balance, and other things. I was advised that RAW is the best when needing to have more flexibility in post-processing, but I do not understand why I cannot import them. I’ve read something about converting to DNG, as well as that my camera model may be too new to allow for import of RAW files to LR3. Can you help?

  14. 31
    ) Andrew
    July 25, 2011 at 4:28 am

    Hello Nasim,
    You wrote that DNG in 15-20% less than original RAW. I wonder where it cuts the corners.
    Does RAW contain a lot of waste in it or DNG uses better lossless data compression algorithm?

  15. 32
    ) Radek
    September 15, 2011 at 10:04 am

    Hi,

    Thanks for the informative article. I am in process upgrading my computer for my photography hobby and I took that opportunity to revisit raw (Nikon NEF files) vs. DNG dilemma which brought me to your site.

    I am certainly drawn to openness of the DNG format, but I find embedding corrections/adjustments to the DNG file to be a bad thing. I find myself coming back to my older pictures after some time revisiting my post-processing choices and often process my images differently as I grow as a photographer. That might as well mean keeping original (unprocessed) DNG file as well as modified ones which effectively negates storage advantage.

    On the other hand I wonder if using programs such as Lightroom or Aperture which use nondestructive image processing preserve DNG files and store corrections separately.

    At any rate, I still have some thinking to do and tests to run :-)
    Thanks for helpful post!
    R>

  16. 33
    ) Scott
    September 19, 2011 at 12:48 pm

    This is a reply to chuck king who was concerned when his raw photos showed up the way he shot them (with the white balance he set, etc) instead of looking completely unprocessed when he looks at them.

    All raw processing or conversion programs have to apply some settings to display a raw file on your screen. There really is no way to view a completely unprocessed raw file unless you’re really good at reading and interpreting a lot of numbers yourself on the fly (like in The Matrix). The program processes the raw data in some way to display it to you, or displays the jpeg file. How it chooses to process and display the data vary from one program or converter to another.

    Depending on the software you use, it may default the processing to very different settings (assuming you’re not seeing the embedded jpg version or thumbnail). For example, if you’re using the raw conversion software that came with your camera it often defaults the processing to the settings you used when you took the photo. But these are only defaults and doesn’t indicate that the sensor data was stored the way you’re seeing it.

    In addition to the raw sensor data, most raw formats store data about the white balance and other parameters that the camera was using as metadata. This means the settings are not part of the sensor data, but are data about the sensor data (ie metadata) that is stored in the same raw file. If you use the raw processing software that came from your camera manufacturer, it has usually been set to read the metadata about how you were shooting the photo and automatically applies those same processing settings to the raw data on first display until you change them. It has to start by displaying the picture by processing it in some way, so why not some reasonable settings?

    The customized SilkyPix processor that comes with all Pentax DSLRs works this way. It knows the white balance, etc, from the metadata and initially processes and displays the raw data based using these settings since they’re somewhat likely to be useful as a starting point.

    I’ve often forgotten to change my white balance in my camera (for example going from incandescent light to shooting in daylight) and when I first opened my raw file in SilkyPix it would apply the incandescent setting to the daylight shot making it look icky and very blue. All I had to do to get a more reasonable setting was choose “Daylight” from the white balance drop-down and it looked good again since it simply changed the processing settings it was applying.

    If you’ve ever tried fixing a jpg shot with a dramatically wrong white balance, you know it’s not very easy and you may never get your photo to look quite right since the jpeg has thrown data away and it’s missing forever now. You don’t have these difficulties with raw files since the file has all the sensor data and can process the photo however you specify using the converter software. When you change settings, it processes it all over again from the original data so you don’t need to worry about it if the program opens with certain settings applied. Just un-apply the settings you don’t like and you are no worse off because it defaulted to displaying one way or another at first.

    Some raw converters such as the one that comes with Photoshop may be more neutral than others, but they’re still processing the data in some way for initial display. I notice that it defaults to 25% sharpening and a medium tone curve (I think this is it since I don’t have the program in front of me). Though it doesn’t attempt to white balance in quite the same way that SilkyPix does from the camera metadata. If/when I don’t like these settings I can change them, and I believe the converter can be customized to use different defaults when opening a raw file.

    So . . . after the too long explanation . . . if you don’t like the default settings your raw converter is applying then you probably want to change them. It really hasn’t destroyed your photo by opening it with certain settings. When you change the settings, it’s changes the processing *from the original sensor data* and isn’t working in a lossy way and layering your changes on top of changes it has already made. It always starts processing from the original sensor data, so you can change settings as much as you want in the raw converter until you get them how you like without worrying about destroying your photo because you tried too many processing settings.

  17. 35
    ) Harlem
    October 22, 2011 at 8:24 pm

    Hello Nasim,
    Reading your articles has been very informative and encouraging! I’m a amateur photographer who has become more and more involved on photography. I am starting to organize my pictures using your system through Lightroom 3 and came across this article in regards to RAW vs. DNG, and I noticed that you don’t speak about dng. What is the difference?

    Thanks for all that you contribute!
    Harlem

  18. 36
    ) Julie
    November 1, 2011 at 11:35 am

    Hi,

    I was wondering if you have found any way, either with RAW or DNG, to have the photos imported into lightroom looking closer to the JPEG preview in the back of the camera. I do realize that this is just a camera interpretation of the original file, but it would save many hours to have it look closer to what I see on the back of the camera, since that was how I was trying to capture it.

    Thanks for your time and info.

    Julie.

  19. 38
    ) Iman
    January 14, 2012 at 9:47 am

    I have lost my DNG files after a HDD crash. Most softwares do recover all the content of the HDD but the DNG files. Do you have any solution to recover the DNG?

    • January 22, 2012 at 12:41 pm

      Iman, who told you that software does not recover DNG? Recovery software should get back ALL the files you had, as long as they have not been overwritten by anything else.

  20. 39
    ) Antonio Luiz Brandão Squadri
    January 22, 2012 at 11:45 am

    Dear:

    I did not undestand your comment “My backup process is actually simpler and smoother now, because I do not have to worry about selecting only sidecar files for backup – I just backup whatever photos I work on.”. Could you explain me how you have worked with RAW files and how you are working today?

    Thank you very much,
    Antonio Squadri

    • January 22, 2012 at 1:36 pm

      Antonio, camera RAW files are proprietary, which means that software like Adobe Photoshop/Lightroom cannot make any changes to it. That’s why they create a sidecar file when you process the image, because that’s where all the changes/adjustments are written to. If you convert to DNG, you only have one file to work with and all changes are added to that file (the original RAW data is not touched, only additional data is written to it). Hence, you have twice less files in your computer. The rest of the info is provided in this article.

      • 53
        ) Mike P
        July 18, 2012 at 9:14 pm

        I am wondering: how do you find the sidecar file and the original RAW image file? How is it separated and how is it identified on your hard drive and in Lightroom? Thanks!

        • 61
          ) Ewa
          January 25, 2013 at 8:51 pm

          This is simple: the sidecar files have the same name that the RAW files, just a different extension: for example IMG_1234.cr2 file will get a sidecar file named IMG_1234.xmp. They are stored in the same folder, so if you see the pictures folder, the files are just one by another. Easy to find :)

      • 71
        ) nestor
        June 25, 2013 at 4:04 pm

        Hi Nasim

        I have a clear understanding about differences between RAW and DNG.

        But today june 2013 how do you think CC Adobe strategy will affect it (DNG)?.

        Will it be an open standard in the future, of perhaps a propietary one?.

        It would be nice to have an article on how you perceive DNG future.

        Many thanks for your excellent site.

  21. 42
    ) Antonio Luiz Brandão Squadri
    January 22, 2012 at 2:52 pm

    How could I extract manually RAW files from DNG ones? Could I extract the original RAW file even after many adjustments?

  22. 43
    ) Peter Wreford
    February 8, 2012 at 2:44 pm

    I have a Nikon P7100 camera which saves it’s raw files as *.NRW extension.
    How can I convert these to *.DNG extension?

    Regards, Peter

  23. 44
    ) Joff
    March 2, 2012 at 4:12 pm

    thanks for this article, I now have a better understanding of dng files. :)

  24. 45
    ) Jeojeo Serrano
    March 11, 2012 at 9:11 pm

    thanks for this artice, i understand the differences between dng & raw as what ou said that dng and raw are the same. i have question cuz i always shoot in raw but the problem is i can’t open in photoshop cs5 the raw files so i need to convert in dng in lightroom 3 my question is even i converted into dng files in lightroom, the quality of raw file is still the same like raw files? is it true that croping the image will loose the quality or pixels of an image? thnak you and more power sir hope you will answer all my question thnak you and best regards….

  25. 47
    ) Bill Cassill
    June 3, 2012 at 4:58 pm

    Sorry, late to the game, I just found this when searching on whether to use NEF or convert to DNG on import to Lightroom. My understanding is, if I convert to DNG, then edit in LR4, that the changes are save to the DNG file, I assume to be reflect those changes in other products??

    When I’ve made changes in LR4, then open it in Adobe Elements 10, I don’t see the changes I made in LR4??

    Is there something else I need to set??

    Thanks!

  26. 48
    ) Renier
    June 4, 2012 at 1:28 pm

    Hi Nassim,
    I have been using the DNG format for several years on my Pentax and having recently taken the plunge into D800 territory it is interesting that a D800 NEF file (74Mb) converted with the DNG 6.7 convertor “weighs out ” at 39Mb with all the frills left out. Just converting it actually increases the file size.

  27. 49
    ) Kathleen
    June 11, 2012 at 12:10 pm

    Hello Nassim,

    Thanks very much for this website. I agree with the person who said there’s a warmth about it that’s appealing – in addition, of course, to the photo info.

    I have a D7000 and sometimes photos are imported into Lightroom as DNG, sometimes as CR2, and sometimes as NEF. I always choose “convert to DNG” so don’t understand why this happens. And I don’t understand what NEF and CR2 are. (I, too, don’t use NX2. I go straight from the camera to LR and then, sometimes for more editing, to Photoshop.) By the way, I recently upgraded to LR4, if that makes any difference.
    Looking forward to your answer.
    Thank you.

    • 51
      ) Anto
      July 14, 2012 at 10:06 pm

      I never have photos as CR2 from my D7000. Maybe that stands for some uncompressed lossless RAW or compressed lossy or any other combination? Do you have NX2 installed?

      • 56
        ) Fableblue2010
        October 23, 2012 at 8:06 am

        CR2 is the Canon RAW format. I do not know why LR4 would be converting any files from a Nikon into a Canon format. Also NEF – Nikon RAW format.

  28. 50
    ) Anto
    July 14, 2012 at 10:03 pm

    One aspect that isn’t touched is performance.
    While DNG is supposed to be a little bit faster in Lightroom (i.e. why else woulds they have Embed Fast Load Data option in DNG settings) many people have all photos on huge external or internal slow HDD storage while working from SSD drives.

    So I wonder what makes more sense performance wise: NEF or DNG files on HDD with ACR and Lightroom preview cache on SSD? I mean if there’s any difference in previews caching and processing of RAW and DNG that would effect the performance when using fast drive for caching but slow one for storage?

  29. 52
    ) Kathleen
    July 15, 2012 at 9:14 am

    I’m the person who said sometimes the files enter as CR2. My huge error! The CR2 is from my Cannon point-and-shoot. Apologies. But thanks for all the info about DNSG and NEF, etc.

    • 57
      ) Fableblue2010
      October 23, 2012 at 8:10 am

      Please excuse the post that i submitted on your earlier post. I did not see this one until after i posted the comment.

  30. 54
    ) John
    August 20, 2012 at 6:19 pm

    Hello Nasim,
    This site is rapidly becoming my “go to” site for information. I came across this tread just today and thought I would post a question that is more recent.
    With the most recent releases of lightroom ver 4 and photoshop cs6, has the dng limitation of retaining active d-lighting been “resolved”?

  31. 55
    ) Doug
    September 15, 2012 at 6:22 pm

    Thank you for this nice summary, but I believe I’ve found a logic flaw in what you have listed as a disadvantage of the RAW format. You say that if you get a new camera you will need to wait for software companies to update their software to read the new camera’s RAW format. This is also a disadvantage for DNG since you will also need to wait for Adobe to update their DNG converter to read teh new camera’s RAW format before you can convert the RAW into DNG for use in your existing programs. Seems like a push to me.

  32. 58
    ) Ken Brakebill
    November 14, 2012 at 1:14 pm

    Thanks for a most informative site and the opportunity to discuss with fellow photographers!

    Based on the ones I have read so far, there are many great articles about LR on this site, and I intend to peruse more of them ASAP.

    Meanwhile, I have about 1400 images taken with the D600, mostly in .NEF format. I have been editing the .NEF files with View NX2, which saves edits within the .NEF file while preserving the original sensor data. I am about to install LR4 and will update to release candidate 4.3 to get full D600 support. When I import these .NEF files, does LR disregard the embedded edit adjustments that I have made? If not, before importing do I have to first remove these edits from the .NEF files via individual resets in View NX2, or is there a better way? If LR can read the edited .NEF files, and I choose to keep the .NEF format, will LR create the sidecar files for those .NEF files that were edited in View NX2?

    On a related note, where can I find a summary of the approach used by LR to store its catalog? For example, if I rename, delete or move a directory after the catalog is created from the initial import, what must happen for LR to become synchronized again.

    I know these are basic questions. As a new user, I want to avoid making elementary setup mistakes as much as possible.

    I also have a somewhat large .JPG collection from two previous Canon P&S cameras that I will have to decide how to incorporate into LR. I will probably also start shooting RAW files with the S100 since I will have a way to edit with LR.

    I have not decided whether to convert to .DNG from .Nef. It seems like a good idea, but the loss of certain camera specific data may not be a good idea. I just don’t know enough to decide yet.

    Thanks in advance for all responses!

  33. 59
    ) John Schuster
    November 20, 2012 at 1:20 pm

    As an archivist, I feel that more metadata is always better than less. If DNG strips away some of the metadata, it seems to me to be less valuable as an archival format. Adobe has submitted to the ISO for approval as an international standard just as they did with the various versions of PDF. Until the ISO approves DNG as a standard, it seems that DNG is a less robust standard from an archival standpoint.

  34. January 22, 2013 at 6:08 am

    Hello Nassim
    Thank you for all the helpful information on Dng.

    I have encountered a problem with file adjustment using ACR due to my only using external harddrives.
    That is, as as I am finding, the Xmp. file will not travel with the Jpg. file, and so uploading adjusted files, which look great in Bridge,to my Web site or Flickr shows only the original unadjusted photos.
    So my questions are :

    a. Is converting Jpg. files to Dng. OK. ( I would normally work with Raw but I travel a great deal and use Jpg. to make it easier and safer in India to save Camera cards to Disks.)

    b. Is Dng. the solution here?

    I was also a little confused by your comment under – The disadvantages of Dng.

    ” Because all changes are written into the DNG file, you would have to back up the entire DNG file every time you make changes to it.”

    Does this mean that changes are not recoverable and you are unable to undo further settings and adjustments ?

    I use Nikon D7000. and Adobe CS5. Most of my post processing work in ACR. I will shortly be taking on Lightroom.

    I hope that you will find time to reply and I would like to thank you in advance if you do.

    With kind regards
    Tim

  35. 62
    ) Sandy Sorlien
    February 8, 2013 at 2:06 pm

    Hello, thanks for the helpful article. I am way back in CS3 and just bought a new Canon 6D and cannot open my CR (Canon Raw) files without the converter. I am very pleased I do not have to spend (another) fortune to buy CS6, but can quickly convert all the RAW files to DMG – it is quite fast. Like the previous poster, I’m confused by this comment:
    ” Because all changes are written into the DNG file, you would have to back up the entire DNG file every time you make changes to it.”

    Wouldn’t you just make a Save As (to Photoshop) of the changed file, the same as you would when you make changes to the RAW file? I haven’t worked with RAW very much and don’t understand the nuances.

    Thanks,
    Sandy

    • 63
      ) Gary Grinaker
      February 8, 2013 at 6:44 pm

      That’s a good question Sandy.

      All the alterations to a RAW file are saved in a tiny sidecar file ending in xmp. Being so small, it takes next to no time to save. The large original RAW file remains unchanged and thus doesn’t need to be saved again.

      In contrast, the DNG file contains both the information from the large RAW file plus the alternations otherwise kept in the xmp file. So instead of quickly saving a little xmp file, the entire large DNG file has to be saved.

      The few seconds of time difference is not all that important if you’re only saving a single file. But if you’re adjusting an entire folder of files (like when applying a color profile to an entire folder filled with vacation photos) , saving all those DNG files will take significantly longer than saving the xmp files.

      In either case the original RAW data remains untouched.

      ~ Gary

  36. 64
    ) Jarno
    March 21, 2013 at 8:21 pm

    Thanks for the article!

    I decided to do RAW-to-DNG conversion for my whole photo archive under Lightroom. Some 15k+ photos / 100GB. The fundamental reason for me was long-term compatibility / archival security. I want to be able to access the photos tens of years later.

    However, as the author mentions, there is one significant downside of storing “negatives” in DNG vs. RAW+XMP format. Your backup size will grow enormously. Every single time you save metadata changes or image edits to the file system (in addition to LR catalog) you will be saving tens of megabytes vs. few kilobytes per file. And when you do this for 10k+ images, your backup archive starts to grow huge. This is not a problem if you never touch the images again, but I am currently in transition phase to move into LR-based library management / tagging / geo-tagging vs. pure file-based approach and edits do happen.

    This problem can of course be fixed with money and adding more Terabytes into your NAS/computer.

    One way to control this is save changes into file system less often and rely more on LR catalog to store the metadata.

  37. 65
    ) Marius Voicu
    April 23, 2013 at 5:22 am

    Hello Nasim,

    I really found this article very straightforward and to the point. Some friends of mine sent me some DNG foto files and wasn’t sure if I can open them with Lightroom or other software.

    I do have some comments about DNG vs. RAW after reading through your article:
    1. I will keep working with RAW because of one single aspect : the RAW file is not written over and lose the data when you apply changes in either software (Lightroom, Photoshop, etc.). This pretty much says it all. The fact that DNG files are written over and you have to back up your collection before attempting to modify a photo just isn’t working for me. You end up occupying more space than you would have with the RAW format. Personally I am not bothered by the size of the RAW files, but if I want to make some new modifications to them I can start from scratch without loosing any data.

    2. The fact that DNG strips some info from the photo doesn’t make me very happy. I want to have all the data at my disposal to modify it from every aspect. I am willing to trade that over the simplicity of viewing the DNG with free software, instead of buying Lightroom.

    That would be my opinion on DNG vs. RAW comparison.

    Again, thank you for the article and all the best to you.

    Marius Voicu.

    • 66
      ) Ryan Beuke
      April 24, 2013 at 6:13 am

      “1. I will keep working with RAW because of one single aspect : the RAW file is not written over and lose the data when you apply changes in either software (Lightroom, Photoshop, etc.).”

      Am i missing something i thought that lightroom would not overwrite anything rather just make a changein the lightroom catalog/db and leave the DNG file alone. Obviously that is not the case with Photoshop but i always export into photoshop as a tiff file and immediately save another copy that i make my changes to.

      • 67
        ) Jarno
        April 24, 2013 at 9:07 pm

        Some people (like me) prefer to write the changes made in Lightroom to the filesystem too as a backup for catastrophic LR crash etc.

        I switched to DNG and now I am running out of backup space. I wish there was external XMP option for DNG’s too.

        • 68
          ) Ryan Beuke
          April 25, 2013 at 6:27 am

          I don’t know how you have your workflow setup or what your budget is but one thing you may want to look into if your running out of backup space is to use a service like crashplan in conjunction with cheaper external USB drives instead of more elaborate Arrays using a drobo, Ready nas, synology, home nas, etc.

          I have used crashplan (100.00 a year) for almost a year now a without problems. It has unlimited space and does not delete old copies of files like some of the other services therefore you can delete files and they still stay on the site. Alternatively you can just sync what is on your data/backup drive and have the other unused data roll off after a period of time. I assume that the files you are backing are the ones you want to keep and you delete the rest which also saves space.

          If you have a good connection you can backup a shoot in around 1 night.

          My process is like this.

          1) OS with Catalog on SSD
          2) Data from shoots get transferred from my camera to a raid 5 array on the PC 4 d 3 tb drives Net 9 TB space.
          3) i have 3 external 3 TB USB drives i got on a sale at Christmas for 120.00 a piece
          4) After the data is copied from my camera to the data array and imported into lightroom i run a backup job which immediately copies the data to one of the three usb drives based on year.
          5) At the same time Crashplan starts backing up my data to the cloud and on my Cable modem service which gets around 15 Mbit/s upload i can backup around 16 gb in around 1 day.

          • 73
            ) Jarno
            July 5, 2013 at 2:37 am

            Yes, I do use Crashplan (some 150GB of photos there) and then 2 other redundant backup strategies (Rsync + rotation scheme on server, separate USB disks in different locations). I have tested CrashPlan restore few times and there have been few small issues, but never with photos though. I think I have all together 14 disks ~dedicated to backup… (yeah, feel free to call me a paranoid).

            The switch to DNG increased the size of my photo backup from ~150GB to 900GB. The reason is that I started to use LR’s library functionality more and attach metadata (location, tags). Every time I do a minor change to metadata the whole DNG file gets overwritten.

            Having DNG with separate xmp sidecar would be a great thing to have. It would be also easier to track changes to files since there are only very few cases if any when the DNG files would need to be re-written.

            But I also should have done my tagging first for the old photos and only then convert to DNG. My bad.

  38. June 17, 2013 at 1:50 am

    Hı Nasim…. very efficient entry thanks….
    I want to ask a question. Did you see a difference between jpg images? DNG-jpg / CR2/jpg

  39. 70
    ) Murk
    June 25, 2013 at 1:04 pm

    Hi Nasim,

    If I wasn’t already convinced of using DN,G your article would have convinced me. Thank you for that. The only real disadvantage is hat you cannot use your Canon DNG’s in the (free!) Canon utilities, where you have a good HDR function. And you lose the information of the Auto Focus points in DNG.

  40. 72
    ) philippe
    July 4, 2013 at 9:09 pm

    Just because of the need to “back up the entire DNG file every time you make changes to it” I do not favor DNG. That being said I do like the fact that DNG is an Open Format, so I will look into the possiblity of saving in Read-Only DNG and keep sidecar xmp files

  41. 74
    ) david
    July 14, 2013 at 12:34 pm

    hi there,
    Thanks for the explanation.

    It went into enough detail so i understand but not so much detail that i got lost on the journey.

    This economy of effort ( on both the writer and reader) is a real skill that is different to the knowledge of subject.

    Sometimes knowing what to leave out of a description is as important as knowing what to include.

    Very thankful and appreciate the effort.

    David

  42. 75
    ) Danilo
    August 14, 2013 at 5:25 pm

    I use Photoshop C6, How can I convert my raw files to DNG?

    • 76
      ) murk
      August 15, 2013 at 1:07 am

      Hi Danilo,

      You can convert your RAW-files when importing them with Bridge, the file handling utility that comes with Photoshop.

      Murk

  43. 77
    ) Darrell Rauwerdink
    November 24, 2013 at 5:43 pm

    I have converted many of my files to dng and eventually deleted nef. I recently decided to trial the new DxO converter and find that none of the dng files are supported. I can only open files still in nef or if I convert dng to tiff but find no metadata carries over. It appears Adobe has provided an open format that requires lifelong allegiance to adobe. I have been using Lightroom for past several editions.

  44. 78
    ) Harish Nair
    December 24, 2013 at 10:32 pm

    I cant open My Raw files of Nikon D5100 in Photoshop CS7. Please help. I am using Windows 7

  45. 79
    ) Tony Worth
    February 3, 2014 at 5:06 pm

    Hi Nassim,
    I recently bought a Panasonic Lumix G6 and found that my Photoshop Elements 10 will not allow me to edit the RAW files as the plug-in for RAW conversion does not include the RAW from this camera. My options were to update the RAW plug-in by purchasing Elements 12 (quite costly) or download the Adobe DNG Converter (for free!). Having read quite a few articles about DNG I have downloaded the converter, but I have found that when I convert the RAW image I get a DNG file that is over 3x the size, where in your article above you say it should be smaller than the RAW file. I have not ticked any boxes that might increase the size of the file, so I’m wondering why I’m getting such big files. At present I’m now thinking of buying the Elements 12 (or another editor) so I can just use the RAW files as they are. Any comments would be most useful. Thanks

  46. Avatar of Michael
    80
    ) Michael
    February 6, 2014 at 1:04 pm

    Nasim-

    Please forgive me for not taking the time to read through all these wonderful comments. I am probably going ask a question that has already been adressed. Anyhow, my question has to do with your last paragraph regarding saving your files in RAW “until (you) back up (your) photos to at least two separate hard drives”, at which point you “purge” your NEF files. Are you saying that everything remains in RAW format, from import to edit to export/backup and when you are finished working on these files, then and only then do you convert everything to DNG? My apologies if this seems like a silly question. Thank you in advance. I absolutely love your content. Maybe you can make more youtube videos? haha.

    Mike Edwards
    http://www.mikeedwardsphotography.com

  47. 81
    ) David Bernarad
    February 8, 2014 at 10:09 am

    If I convert to DNG, where in Lightroom do I find the original NEF files?

  48. 82
    ) Jamie
    February 18, 2014 at 11:59 pm

    Hello,

    Thank you for this awesome piece of information! I guess Im on the right track using DNGs. I do have a question. I post most of my photos online, facebook mainly… but my pictures tend to almost always lose quality. How do I save my images to get that sharp image quality view on facebook/online? When editing photos, does the image lose quality as well?

  49. 83
    ) Tony Worth
    February 20, 2014 at 4:17 pm

    Ref my comments in 79 above, it would appear that I had set up the Adobe DNG converter incorrectly in the ‘Preferences – Compatibility’. Now I have reset it to ‘Camera RAW 7.1 and later’ it produces DNG files that are smaller than the original RAW file.

  50. 84
    ) Nancy
    April 11, 2014 at 5:27 pm

    Thank you for this helpful informaion and your website. I have a bit of a dilemma maybe you can help me with. I use a Pentax K30 that only saves RAW files in dng (not pef as some Pentax’s do). I belong to a photography group that has a contest entitled “Basic Photography” (because they are looking for the photographer’s pure photographic capabilites, not his capabilities as a post-processing artist). Therefore, they will only accept RAW files, and furthermore, their rules specifically state that they WILL NOT accept a dng file. When I queried the contest curator, explaining to him that a dng file is RAW, he tells me that a Canon or Nikon RAW file cannot be altered or edited and then resaved as the same type of file (same file extension), but that a dng file can be altered and then resaved as a dng file. The thinking is that a person could ‘cheat’ when using the dng format. Is their information correct and if you could explain why or why not it would be most helpful.

    There is no monetary or physical reward involved in the contest, but I would like to participate if possible.

  51. 85
    ) Nasariv
    May 25, 2014 at 11:43 pm

    Nasim,

    Tried processing a RAW file in photoshop elements 12, but when it came to saving the processed image, it could only be saved as a dng file.

    How can I change the dng file to a TIFF or JPEG.

  52. 86
    ) Nasariv
    May 25, 2014 at 11:45 pm

    Processed a RAW file in Photoshop Elements 12 but when it could only be saved as a DNG format.
    How can it be converted to a TIFF or JPEG.

    • 87
      ) Vic
      June 11, 2014 at 4:52 pm

      Nasariv,

      you process a raw or dng file in Elements ACR which is opened in Elements for process as a tiff of jpeg, you then use “Save as” and you should get window open with all your options.

      You can convert a Raw to DNG but not process one to the other. Neither a RAW or DNG file can be altered and no alterations are save in either as some mentioned in above posts. Alterations for Raw are save as .xmp and in DNG the alterations are save in the backup of the software you are using like LR, your original RAW or DNG’s files are not backed up. Your preferred software remembers where these files are in the Catalogue structure and if they are moved or removed directly from where the catalogue is on your hard drive, your software won’t be able to find them.

      Remember that in Lightroom only the alterations of each file will be backed up and this backup should be on external drives for safety, more then one if possible. If you have a disaster and loose your backup you loose all your alterations you ever have done in your entire catalogue.

      Hope this helps, Regards

      Vic

  53. 88
    ) Patrick Kelly
    August 7, 2014 at 5:02 pm

    Hi.

    Just purchased a digital camera for the first time, the model is a canon 5d mkIII what do I need to do so that I can download my prints from the raw format. Do I need to get software and if I do what do I need to get. If you can give me any assistance it would be very much appreciated.

    Kind regards.

    Paudie. (Patrick Kelly)

    • 89
      ) George
      August 28, 2014 at 12:19 am

      G’day Patrick,

      The Canon 5D MkIII will have come with a Software Solutions CD. Along with other things, it will have the EOS Utility which is for downloading the camera files into your computer. It will also have Digital Photo Professional on it. This is the basic software specifically for viewing, editing and exporting or converting Canon RAW files. If you wish to use a more comprehensive photo editing package, Adobe Lightroom 5 will fit the bill. It will also be able to directly process your RAW files, and so much more.

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