Copying a subset of the tags using a shortcut file

[Archive]

[Originally posted by yannick on 2005-07-15 18:06:03-07]

Hi,

I am trying to copy a subset of tags from a raw file (NEF format) to a derived jpeg file using a shortcut file.  I try to achieve this using "exiftool -tagsfromfile source.nef -NEF dest.jpg", but it fails with the error:
No writable tags found - raw/20050702_174841.nef
    0 image files updated
    1 image files unchanged

Viewing a subset of tags using "exiftool -NEF source.nef" does work.

Is what I want to achieve simply impossible with exiftool, or can anybody tell me how to proceed?

Greetings,

Yannick

[Archive]

[Originally posted by exiftool on 2005-07-16 11:12:18-07]

Hi Yannick,

Thanks for pointing out this oversight.  ExifTool wasn't expanding the shortcuts used with the -tagsFromFile option.

I have fixed this and released ExifTool version 5.43 with this ability.  The new version is now available from my web site.

- Phil

[Archive]

[Originally posted by yannick on 2005-07-16 13:32:33-07]

Hi Phil,

Thank you for your quick response.  I downloaded and tried your new version.  It works now, but I seem to be unable to include the "Aperture" tag (maybe some others as well) in my shortcut file.  The following doesn't work either: "exiftool -tagsfromfile image.nef -Aperture image.jpg" (No writable tags found - image.nef).  Copying all tags using "exiftool -tagsfromfile image.nef image.jpg", does include the Aperture info.  Displaying the tag using "exiftool -Aperture image.nef" does work.  

Yannick

[Archive]

[Originally posted by exiftool on 2005-07-17 12:41:54-07]

Hi Yannick,

I just had the thought that you would run into trouble trying to copy part of the information so I dropped by to leave a note.  However, you are having trouble for a different reason than I anticipated.

Your trouble is with tag names, and is one of the questions in the FAQ. Run "exiftool -a -S -G1" to see the tag names and their location in the file.  The "Aperture" tag is actually a Composite tag and is not writable, you want to set the FNumber tag.  You can either copy the FNumber over from the NEF (with "-tagsFromFile -FNumber"), or write the Aperture to the FNumber (with "-tagsFromFile '-Aperture>FNumber'".  In this case the result will be the same because Aperture is derived from FNumber in Nikon files.  (But for other brands, it may be derived from other tags.  The Aperture tag is provided to give a consistent tag for extracting aperture across different brands.)

The problem I thought you might have is that you won't be able to copy part of the maker notes.  For various reasons, ExifTool will not add or remove individual maker note tags.  So it is all or nothing for tags in the "Nikon" group.  You either copy all of the maker notes, or nothing.  To copy all of the maker notes, use "-tagsFromFile -MakerNoteNikon" tag, but if you do this you must also add "-Make -Model" for ExifTool to have the necessary information to be able to decode the maker notes when reading the file afterwards.

I hope all this makes sense.

To summarize: For writing individual tags to a JPG file, you should only be looking writing EXIF, IPTC or XMP tags, not MakerNotes or Composite  tags.  (These are general location names, shown with "-G0".)

[Archive]

[Originally posted by yannick on 2005-07-18 19:08:21-07]

Hi Phil,

Thank you for the explanation.  You were right on both items: the other tags that would not copy were indeed part of the maker notes.  With your recommendations I am now able to do what I intended to.  This is a very usefull piece of software!

Yannick