20 Replies Latest reply on Oct 6, 2009 8:02 PM by Hudechrome-sd9sPI

    Questions About DNG

    Hudechrome-sd9sPI Level 2

      1) Is the Current DNG 5.5 only useable in CS4?

       

       

       

      2) I notice that support for cameras is shown for both RAW and DNG. Since DNG is supposed to be universal, what is the down side of using DNG to run raw files from cameras such as the Canon 7D? Should I be using DNG 5.5 on CS3 for this camera? An earlier one?

       

      3) What would be the observable differences between a supported and non-supported when converting to DNG?

       

      Message was edited by: Hudechrome

        • 1. Re: Questions About DNG
          ssprengel Adobe Community Professional & MVP

          "DNG 5.5" means what, the version of the converter or some sort of version of the DNG specification?

           

          Each camera has one or more camera-profile(s) determined by Adobe and these must be known to the Adobe RAW engine which uses them or to the DNG converter which embeds them.  The 7D's camera-profiles are only beta at the moment so there may be improvements to them when the 7D is fully supported.

           

          A non-supported camera's RAWs cannot be converted with the DNG Converter because to convert it needs to know the camera-profiles and, at least to me, "non-supported" means the profiles are not known, so the observable difference would be that there is no DNG.

          • 2. Re: Questions About DNG
            Hudechrome-sd9sPI Level 2

            DNG 5.5 is the current download of DNG.

             

            The unsupported camera here means a new camera in a series, in this case, Canon 7D. It's file extension is supported but the 7D is not. Therefore conversions are possible, I am doing it as I write. My question has to do with the fact that the 7D is not listed. What ia the difference in the DNG file once the camera is listed?

            • 3. Re: Questions About DNG
              JimHess-5IFZWq Level 3

              There is no difference in the image data in a DNG file compared to the original raw image.  DNG is simply a new type of container to house all of the image data in a "standardized" format.  One of the big advantages of using DNG as opposed to the original raw image is that the metadata changes are stored within the DNG file itself rather than in a sidecar XMP file.  This can make the DNG files a little more portable.

               

              The DNG converter version 5.5 will convert images from the most cameras.  Those DNG files are compatible with all versions of Camera Raw clear back to version 2.4 in Photoshop CS.  This means that you can have images from the latest camera supported by Camera Raw, convert it to a DNG file, and edit it in Camera Raw version 2.4 and Photoshop CS.

               

              If Camera Raw does not support a specific camera model, then it will be necessary to wait for an update from Adobe.  This is true not only of Camera Raw but also the DNG converter.  I am puzzled about your 7D.  Support must be added for each camera model.  If the DNG converter will actually convert the images from the 7D then that would imply that there is preliminary support for that camera in Camera Raw itself.  This happens occasionally, especially in beta versions.  Since I am still using Photoshop CS3 and Camera Raw 4.6, I am not aware of what cameras have been added to the most recent version.

              • 4. Re: Questions About DNG
                Hudechrome-sd9sPI Level 2

                It will convert the full size (18 MP) files but not the smaller ones from the 7D. We are seeing a magenta cast to clipped highlights from the 7D

                in ACR, but when the file is subsequently opened in CS3 (but not CS 4), the color cast disappears.

                 

                Also, the files from the 7D appear noisy, even the iSO 200 files.  Comparing the exact same shot between a D90 and the 7D, Dfine "cleans up" the 7D file, but there is barely a change in the Nikon file. Important detail from the 7D is lost.

                 

                Since there is a 14 day trial period involved, we need answers, but most likely not forthcoming.

                 

                Message was edited by: Hudechrome

                 

                Message was edited by: Hudechrome

                • 5. Re: Questions About DNG
                  ssprengel Adobe Community Professional & MVP

                  If you look in the Camera Calibration tab of LR or ACR, you will see a Camera Profile downdown list.  For most Canons and Nikons there is a whole series of profiles available.

                   

                  For the 7D, which is not documented as supported, there is only one profile, called Beta.  This tells me that there is only a preliminary profile embedded into the newest DNG Converter, ACR and LR for the 7D and the next versions of each will fully support the 7D.  Since ACR 5.5 just came out, it may be some months before a new version is released that fully supports the 7D, unless Adobe feels like doing something else.

                   

                  Do you have an example RAW you can post, somewhere, or a link to an already posted online example, that is susceptible to the magenta cast?  I am not affiliated with Adobe, just curious.

                   

                  The color-cast may be there or not depending on the output color-space from ACR.  If you have this set as the relative wide ProPhoto then perhaps the cast, remains, but if you set it to sRGB, perhaps it is clipped?  Just a guess, since I don't have a file to try.

                  • 6. Re: Questions About DNG
                    Panoholic Level 2
                    1) Is the Current DNG 5.5 only useable in CS4?

                     

                    The DNG converter is a stand-alone program, i.e. it is running without CS, LR or Bridge. 5.5 is the version of the program code (click on About in the dialog). The "usability" is determined rather by the version of the DNG format: older versions of CS do not support features, which have been introduced in newer DNG format versions.

                     

                    The DNG format can be selected in the DNG converter dialog: Change Preferences -> Compatibility.

                     

                    As the Canon7D does not require any new features, the resulting DNG file can be used in CS3 or even in CS2, even if the conversion specifies a higher DNG version.

                     

                    3) What would be the observable differences between a supported and non-supported when converting to DNG?

                     

                    If the DNG converter does not support a camera, it will not process the file. The speciality in this particular case is, that the 7D is not mentioned as "supported", because the support is preliminary.

                     

                    It's file extension is supported but the 7D is not. Therefore conversions are possible


                    The file name extention is irrelevant. All newer Canon raw files have the extention CR2; that does not mean, that the camera is supported by ACR or the DNG converter.

                     

                    We are seeing a magenta cast to clipped highlights from the 7D in ACR

                     

                    Try reducing "Blacks".

                     

                    the files from the 7D appear noisy, even the iSO 200 files

                     

                    The 7D is about as noisy as the 50D at low ISOs, and less noise from 1600. However, all copies exhibit a vertical banding. It depends on the copy, at which intensity and how strong it appears. I have not seen it with ISO higher than 400, and it occurs usually in the 9th and 10th stop of the dynamic range, i.e. you have to increase the intensity a lot (exposure, brightness, fill light) in order to see it (and blacks = 0).

                     

                    Here are two samples for the banding, 100% crops:

                     

                    http://www.panopeeper.com/Canon/Canon7D_BadReadout_ISO00100_PhilipP_0040_Crop.jpg

                    http://www.panopeeper.com/Canon/Canon7D_Banding_ISO00100_Jehuty_DPR_0014.JPG

                    Gabor

                    • 7. Re: Questions About DNG
                      Hudechrome-sd9sPI Level 2

                      Thanks for clearing up a misunderstanding. My bad was to think about .nef or .CR2 as industry standards, like mp3.

                       

                      Anyway, the noise problem appears to be Canon's. Their RAW software output shows no noise after processing, outputting as either jpeg or tif.

                       

                      When converting to dng (it is a beta as the Camera Profile indicates), and opening in Photoshop, the noise is visible and attempting to use a NR program like Dfine does serious damage to the detail. This is not so in the Canon software. The noise disappears yet the detail is solid. This presents a most difficult problem to the user wanting maximum performance from both hardware and software. First run it through the Canon software, then Photoshop. Very clumsy. This is not so with my D90, which which we performed some basic comparisons.

                       

                      So far as DNG conversions, I was given to understand that if one purchases a camera not yet supported in the current upgrades to ACR, one could always convert to DNG and process as RAW. Apparently this is not so. With the 7D, the full size file will convert with the DNG converter, but the smaller and medium size files will not. So a beta version for only full size is present.

                       

                      I did find the Preference>Compatibility selector. I downloaded the current converter and saw the Pref dialog.

                      • 8. Re: Questions About DNG
                        Hudechrome-sd9sPI Level 2

                        Here are two samples of the noise problem.

                         

                        The label tell it all.

                        • 9. Re: Questions About DNG
                          Panoholic Level 2
                          My bad was to think about .nef or .CR2 as industry standards, like mp3

                           

                          They are "proprietory standards", i.e. all CR2 and all NEF files follow some common rules, although the camera manufacturers are never shy to violate their own rules or those of others, apart from constant changing and addition - all that without any publicized documentation.

                           

                          However, that's not the main issue. In many cases the format does not change the least, but that does not mean, that programs can immediately and correctly process the files. Certain characteristics change practically with each camera model and the raw processing program has to be prepared for the new camera. Exceptions are seldom, like the Nikon D3/D700 or the D300/D300s, because they have the same sensor and same electronics.

                           

                          When converting to dng (it is a beta as the Camera Profile indicates), and opening in Photoshop, the noise is visible and attempting to use a NR program like Dfine does serious damage to the detail. This is not so in the Canon software

                           

                          In respect of noise reduction, Canon's and Nikon's (and even Sony's) own raw processors have always been better than ACR in really noisy cases.

                          However, this is not a fair comment regarding the 7D, as its support in ACR is preliminary.

                           

                          I suggest generally not to leave the NR completely to the post processing. If you turn off NR in ACR, the result will be horrendeous, blotchy, and that can't be repaired later. This is in strong contrast to DPP, which can create an acceptable output without NR. Look at the image in 100% and increase the noise reduction parameters, mainly the color but luminance as well, until you see details unacceptably affected.

                           

                          Another important aspect is the sharpening. You can ruin a noisy image with sharpening in ACR. Keep the amount and radius low, like 25 and 0.5. Keep in eyes: this sharpening is not a substitute for the final sharpening, which will depend on the size, output density, etc.´

                           

                          Gabor

                          • 10. Re: Questions About DNG
                            Panoholic Level 2

                            While I was writing my previous message, you posted the samples. I am somewhat buffled, for the ACR rendering is less noisy than the Canon. On the other hand, the Canon rendering is much brighter, and that changes the perception a lot: the originally present tonal differences appear smaller in the higher intensity areas.

                             

                            Gabor

                             

                            ADDED: I measured the noise on the samples with Photoshop and compared them; for practical purposes, both versions are noiseless, but the Canon version exhibits greater standard deviation. The Canon version is sharper as well, and that may have caused the "higher noise".

                            • 11. Re: Questions About DNG
                              Hudechrome-sd9sPI Level 2

                              I don't understand. The dng file has more noise than the Canon. The steps are thus:

                               

                              Create a DNG from the CR2 file Save.

                              Create an output from the Canon software. Save as ..tif

                               

                              Open either file in PS from Bridge; it first opens in ACR where no changes are done. The final image moves to PS where a crop of the top of the barn and sky are done, change to 8 bit, save as max quality .jpeg .

                               

                              Under those circumstances, and looking at the cropped image before saving as jpeg, the DNG is obviously noisier than the Canon. Further, attempting reduce the noise in Dfine shows that Dfine also recognizes the DNG as noisy, reduces the noise and kills the detail. Running the Canon software result through Dfine shows tiny, hardly perceptible change in the image. The Canon processed image is sharper than the DNG processed through Dfine.

                               

                              I realize that this is a rather haphazardly controlled test, but the process employed is close to what a user might do to dealing with the image.

                               

                              I recognize that the brightness don't match, but that is rather moot. I examined the Canon with reduced brightness, increased contrast to force the noise visibility, as well as the DNG. There can be no question in both our minds here, running on CS3 and CS4, that outputting the RAW Canon file as DNG the opening it in Photoshop exhibits much more noise than the control image obtained with a D90 shot at the same time. The Canon processed version and the D90 version match noise characteristics pretty well.

                               

                              It begs the question" Why go to the 7D?

                               

                              Personally, I am not contemplating the change My friend has a 20D he wants to replace, and he was considering moving to Nikon but waited to see the 7D. Having to sell off all the Canon stuff doesn't add up financially, even considering the difference in body price. There is a 14 day window to return the 7D so decisions have to be made soon.

                              • 12. Re: Questions About DNG
                                ssprengel Adobe Community Professional & MVP

                                Are you comparing a D90 to a 7D or a CR2 and the DNG from the CR2 or what exactly are you talking about regarding a DNG having more noise...more noise compared to what, the original CR2 or another camera's RAW file?

                                • 13. Re: Questions About DNG
                                  JimHess-5IFZWq Level 3

                                  I seriously doubt that converting to DNG has anything to do with the increase in noise.  The image data is precisely the same in either the original raw file or the DNG file.  The difference in noise reduction is in the different software you are using.  The software provided by Canon is able to read settings made in the camera that Camera Raw cannot read because those settings are proprietary.  If you open the original raw image in Camera Raw I believe you will find the noise levels will be equivalent to what you see in the DNG file.

                                   

                                  One of the criticisms of Camera Raw and Lightroom is that the noise reduction algorithms need to be improved.  I don't know that, because I don't have any problems with my camera, a Nikon D40.  But I know that others do have the noise problem and have been quite vocal about it.  You need to work with the noise controls in Camera Raw to see if you can reach an acceptable noise level.  There WILL be a difference between Camera Raw and proprietary software from the manufacturer.  What you will have to do is find a reasonable compromise that will produce the results you are looking for or can accept.

                                  • 14. Re: Questions About DNG
                                    Hudechrome-sd9sPI Level 2

                                    ssprengel wrote:

                                     

                                    Are you comparing a D90 to a 7D or a CR2 and the DNG from the CR2 or what exactly are you talking about regarding a DNG having more noise...more noise compared to what, the original CR2 or another camera's RAW file?

                                    I am comparing the noise results of 7D to:

                                    a) the D90

                                    b) The 7D Canon software output against the 7D DNG.

                                     

                                    The intent of the test was to ascertain whether upgrading to the 7D or changing entirely from canon to Nikon is warranted. There are other considerations not in the mix here as well.

                                    • 15. Re: Questions About DNG
                                      Hudechrome-sd9sPI Level 2

                                      I am in perfect agreement with you, Jim, concerning your first paragraph. I think that what we see in DNG is the true picture (pun intended!) of the output of the sensor, sans any defect correction algorithms.  And that is what bothers me. If I have to depend on tricky algorithms subsequent to the output from the camera, where with another camera this situation does not exist, well, we are on the way to making decisions.

                                       

                                      Since Nikon already makes cameras that do not need to have ANY noise reduction in RAW anf that Dfine cannot find noise to reduce, it seems to me the die is cast.

                                       

                                      IMO, anyway.

                                       

                                      Thanks to all who have responded. They were thoughtful responses.

                                      • 16. Re: Questions About DNG
                                        ssprengel Adobe Community Professional & MVP

                                        A 7D has a 14-bits-per-pixel RAW whereas a D90 has only a 12-bits-per-pixel RAW so it isn't unexpected to see more noise and more shadow detail in a 7D image.

                                         

                                        Did you ever compare a D90 DNG to a 7D DNG processed with Adobe software?  To me that is the only fair comparison of RAW noise.

                                        • 17. Re: Questions About DNG
                                          Hudechrome-sd9sPI Level 2

                                          A 14 bit converter will only help if the intrinsic device noise (the sensor) is low enough. If it isn't, the higher bit device will show the increased noise. It doesn't generate it.

                                           

                                          The 14 bit converter has a 12 db lower noise floor that the 12 bit converter. So yes, it will see noise the 12 bit doesn't. But why the hell would you use a 14 bit converter with a signal source that has a noise level now detectable by that converter?  Marry that converter to a newer signal source.

                                           

                                          But that is quite the problem, given all the parameters involved in noise generation and suppression. Better live with it and try for a suitable algorithm. Or maybe go back to  ccd's.

                                           

                                          And then there is the question of the bit depth and sensitivity of the output devices (monitors, printers etc.)

                                          • 18. Re: Questions About DNG
                                            Panoholic Level 2
                                            A 7D has a 14-bits-per-pixel RAW whereas a D90 has only a 12-bits-per-pixel RAW so it isn't unexpected to see more noise and more shadow detail in a 7D image.


                                            There is no such connection. Fact is, the 7D has slightly higher noise than the D90 with up to ISO 800; on the other hand, it has 50% more pixels, and it has better high ISO, effective up to 3200 (perhaps even 6400, I am not sure).

                                             

                                            The more shadow details are due to the higher pixel count, not to the higher bit depth.

                                             

                                            There is another aspect: the D90 compresses the raw data lossily (not selectable, like with the D3 and D300). This can cause banding, but it is really seldom.

                                             

                                            Nothing of that noise is present in the posted samples; on the other hand, if one does not need the 7D's advantages (movie, high ISO, high pixel count), then why pay a lot more than for the D90.

                                             

                                            Gabor

                                            • 19. Re: Questions About DNG
                                              Panoholic Level 2
                                              there is the question of the bit depth and sensitivity of the output devices (monitors, printers etc.)


                                              The bit depth of the raw data has nothing to do with the bit depth of the presentation device. The former is in linear value range, the latter is after the "gamma encoding", which is a "compression" of tone levels.

                                               

                                              Gabor

                                              • 20. Re: Questions About DNG
                                                Hudechrome-sd9sPI Level 2

                                                Oh, well, never mind....