11 Replies Latest reply on Feb 15, 2008 9:51 AM by bokeron2008

    DNG and Maker Notes. And 72ppp.

    bokeron2008 Level 1
      So, another problem that I'm going to be taught it's not Adobe's fault, but the rest of the world not knowing how to code a program, and that Bridge is doing it right. It may be the case, but I have to ask here anyway to be sure, and to understand why...

      Photo Mechanic. Read this small thread. I've encountered the exact same situation.

      http://forums.camerabits.com/index.php?topic=2659.0

      So... are "maker notes" inside a private DNG maker note ? How's that ?
      If so, why ? If not so, what's the problem then ? Can't Adobe make it easier for the rest of software developers ?

      And, what about those 72ppp ? Is a minor quirk, but I'd need it solved too, nonetheless.

      Yes, I know. Go ask Photo Mechanic, Bridge does it right...

      But there seems to be a pattern here for a so called "standard format".
        • 1. Re: DNG and Maker Notes. And 72ppp.
          ArrrBee Level 1
          Once again the DNG specifications are available to developers. It is up to
          them to choose to follow them or not. It is exactly that plain and simple.
          Now other companies may not like the way Adobe has chosen to do something
          and think that they can do it better and therefore ignore the specification
          laid out by Adobe. That is not Adobe's problem that is the problem of the
          ones that chose to do it there way.

          Robert
          • 2. Re: DNG and Maker Notes. And 72ppp.
            Panoholic Level 2
            >are "maker notes" inside a private DNG maker note ? How's that ?
            If so, why ?

            The MakerNote is a group of information consisting of some dozen to over hundreds, even thousands of individual values. The structure of the data, at least on the highest level, is defined in the TIFF specification.

            However, some camera makers chose to violate the TIFF rules. This is almost the norm, particularly Nikon feels free to ignore the rules. The MakerNote is one of the blatant cases - it may or may not adhere to the TIFF specification, depending on the camera. Therefor it can not be simply copied from the native raw file in the DNG file; it is encapsulated and can be used only with the knowledge of that specific raw file.

            The encapsulation in DNG is awkward, but that's only the form; the MakerNote data is there in its original form inside the capsel.
            • 3. Re: DNG and Maker Notes. And 72ppp.
              bokeron2008 Level 1
              Thanks G Sch.
              By your explanation, it looks like the only way to "standarize" the maker notes was to embed them in a standard "capsule", so any method chosen would lead to the same "problem".
              So until DNG has a wider support and users ask software developers to support it fully, this might continue to be an issue.

              Looking at the question now, it seems quite obvious, but until I read your message it didn't really looked that obvious :)
              • 4. Re: DNG and Maker Notes. And 72ppp.
                ArrrBee Level 1
                Frankly I can't say I think very highly of any company that chooses to
                support DNG and then doesn't fully support it or support it properly. But,
                then consumers are in the drivers seat with this, they just choose to
                complain to a company that can't do anything about it instead of telling the
                companies messing it up that you want' be getting any more of my money until
                you do it right. Enough people stop buying cameras and software that don't
                support standards in a standard way they companies will listen. But, instead
                people make little complaints but then turn around and buy their products
                anyways.

                Robert
                • 5. Re: DNG and Maker Notes. And 72ppp.
                  Panoholic Level 2
                  > what about those 72ppp ? Is a minor quirk, but I'd need it solved too, nonetheless

                  I forgot to answer this question.

                  The NEF files do contain the resolution specification, 300dpi (which should be 300ppi). The DNG converter does not change this value but drops it all together. ExifTool displays the default value, which is 72dpi. The poster on that forum believed wrongly, that a changed resolution is present in the DNG file.
                  • 6. Re: DNG and Maker Notes. And 72ppp.
                    bokeron2008 Level 1
                    Robert -

                    I agree, but it has to be taken into account that DNG is still new, still not widely used, and camera makers backup is far from being complete ;)
                    People are still thinking if/how/when to convert their originals to DNG (myself included), so supporting DNG is not a priority right now.
                    I don't really know what the difficulties are to implement it properly...I thought that, given its specification is public, it should be easy for developers to support it. But reality says a different thing, and for me it is/was/dontknowyet easier to believe something about DNG was causing the problems than to believe each and every software developer are getting it wrong. And that's why I'm asking this kind of questions :)

                    G Sch -

                    So, DNG converter drop that bit ? By design ? A bug ? Is this going to change ?
                    And... what can I do meanwhile to add "resolution" back into DNG ? How to do it properly respecting DNG format ?

                    For Nth time, thanks both for taking the time to read and answer.
                    • 7. Re: DNG and Maker Notes. And 72ppp.
                      Thomas Knoll Level 2
                      DNG files do not have resolutions. What is the point? A resolution makes sense for processed files that are ready to print, but is completely pointless for raw files that need processing.

                      The correct thing to display for the resolution of a DNG file is NOTHING. If some software is showing "72 dpi/ppi", then there is a BUG that that software. Complain to the Photo Mechanic people and tell them to stop making up resolution information out of thin air.
                      • 8. Re: DNG and Maker Notes. And 72ppp.
                        bokeron2008 Level 1
                        Even for an unprocessed file, you can not invent pixels, just interpolate. So, knowing what print size I get at what resolution is useful judging what to crop from the picture to avoid extra interpolation. For me, at least.
                        Getting this resolution info visually is easier than having to calculate myself.
                        It is important ? No. Convenient ? For me, yes.

                        On an unrelated note, I must mention that G Sch has just said the same about Photo Mechanic, without the coarse name calling.
                        • 9. Re: DNG and Maker Notes. And 72ppp.
                          Panoholic Level 2
                          >So, DNG converter drop that bit ? By design ? A bug ? Is this going to change ?

                          I am a critic of DNG, not a speaker, that's Thomas Knoll's role. Btw, I woud have answered roughly the same.

                          >And... what can I do meanwhile to add "resolution" back into DNG ? How to do it properly respecting DNG format ?

                          The resolution is a standard TIFF tag (actually, two), they can be added to Exif via different Exif tools. However, I don't see any rational in that. The resolution is not the characteristic of an image; it is the characteristic of the expected printing. It depends on the quality of the image, on its preparation (for example sharpening), on your intention, and not to forget, on the printer.

                          >G Sch has just said the same about Photo Mechanic, without the coarse name calling

                          That was a temporary laps on my side :-)

                          Seriously, as the starting position I don't trust any computer programs, and if I have to, then only mines. I have a program, which lists all TIFF fields as they are, and only those, which are there.
                          • 10. Re: DNG and Maker Notes. And 72ppp.
                            bokeron2008 Level 1
                            The rationale... I mean, my rationale, is that Lightroom is allowing me to edit a file, crop it, and save the expected output as preview, all of this inside DNG.
                            If I have the resolution (the one I've chosen to use, or the camera's default instead) in DNG metadata, and the horizontal and vertical pixels... then I can automatically calculate and show automatically on screen, the print size at that resolution. I usually choose different crops for different print sizes and knowing what print size I'm getting ... helps me.
                            It's not that I can't live without it, but it would make my life easier.

                            Anyways, I think now I see it more clearly, and I'll have to make my mind about doing it or not.

                            Thanks all for your answers.
                            • 11. Re: DNG and Maker Notes. And 72ppp.
                              ArrrBee Level 1
                              DNG isn't all that new. However, because of the lack of an Adobe released
                              Vista codec I am starting to believe that Adobe is just playing around and
                              not really pushing DNG.

                              Robert