Image timestamp metadata

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16 comments

  • Marco Hyman
    Answering my own question:

    Capture One doesn't handle dates before Jan 1 1970. ☹️

    All images imported with earlier dates show no value in Capture One. I find that very frustrating.
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  • SFA
    [quote="marchyman" wrote:
    Answering my own question:

    Capture One doesn't handle dates before Jan 1 1970. ☹️

    All images imported with earlier dates show no value in Capture One. I find that very frustrating.


    It would not be very logical to have any digital files with a date stamp in the 1920s ...
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  • Robert Farhi
    I have had (and still have) this problem with old negative films I have scanned. I asked Phase One about that, and they told me that it is related with Unix time (?). It would be good if Phase One could ignore this limitation, but it seems a little bit complicated for unknown reasons.

    I recovered their answer, dated January 2017:

    This is to do with Unix time as that starts on this default.

    As its before 1970 it will default to this.

    I hope this helps you

    Kind regards

    Phase One Support


    And, later (still January 2017):

    Hi Robert,

    Yes this is a limitation of Capture One using this time method.

    Ill put in a request for it to be reviewed.

    Kind regards

    Phase One Support
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  • SFA
    Computer date systems are constrained, in their basic state, by the size of the data fields available to store the time count as a whole number.

    The default UNIX operating system started from 1/1/70 since it did not exist before that date and there would be no point allowing for earlier numbers (that represent dates) that the system itself would never use. In effect that would just shorten the period of time that the operating system could be used before it required modification to enable it for longer operation span or a rest of the "base date" with the associated problems of dealing with old data and trying to match systems running different base dates.

    A bit like the "Year 2000" problem only more disruptive in reality than Y2K would have been.

    In a database one can establish date fields that work to different base dates and there are some standards for those. Apple, at one point, used 2 different start dates for those - 01/01/1900 or 01/01/1904 iirc.

    Windows development has always used 01/01/1900 as far as I know.

    These mechanisms allow historic dates (or future dates) to be used mathematically in databases for date and time difference calculations and Time Zone adjustments without having to supply a formula to do so and are also, typically, Leap Year aware as well as having other attributes for undertaking various calculations to convert to different counting and measuring systems.

    For IPTC data there seem to be at least 2 optional fields that seem to have been made available to deal with recording dates and times that are not EXIF related - i.e. not the date and time a file was created - such as the data and time of an original digitally created image.

    The "Date Created" field is a Date format field with this usage description:

    "Definition
    Designates the date and optionally the time the artwork or object in the image was created. This relates to artwork or objects with associated intellectual property rights.

    Help Text
    Enter the date and optionally the time when the artwork or object in this image was created"

    So this would appear to related to the the date when an original digital artwork was created, such artwork being the basis for a new piece of work after it has been further modified.


    The "Circa Date Created" field has the following usage description. It is a TEXT field

    "Definition
    Approximate date or range of dates associated with the creation and production of an artwork or object or its components.

    Help Text
    Enter the approximate date or range of dates associated with the creation and production of an artwork or object or its components."

    As a text field one assumes that anything you want to type into it will be accepted. So its primary use would be for information rather than calculation. However the text could be anything so as long as the entries were made consistently or reasonably consistently search for a "date" such as "May 1935" ought to be possible.

    All of that said I suspect that neither of these solutions would be exactly what people are expecting.

    In fact if one is to use text, as per the second example, then any text field in the IPTC section of metadata would do the job. Obviously consistency would be required for maximum benefits and sharing files with other systems using different fields could be unsatisfactory (which is, of course, why the IPTC standards exist and continue to be developed) but it would offer at least some immediate options for recording approximated dates for when objects in historical images were created and the photos or drawings that have recorded them were made.

    For reference:

    https://iptc.org/std/photometadata/specification/IPTC-PhotoMetadata



    HTH and provides some points for discussion.


    Grant
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  • Robert Farhi
    Thanks Grant. I just worked around this limitation by inserting the date of my negative scans of images taken before 1970, in an IPTC field (description, for instance). But this is not an EXIF.....
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  • Marco Hyman
    Yes, it is about UNIX time. That's why I knew to check if it was pre 1970 or not. However, there is NOTHING stopping Phase One from handling negative offsets from the epoch which would allow dates going back to 1834. The proof of this is Lightroom and exiftool and others. They handle timestamps before 1970.

    As for those who say such dates are not logical: Have you never scanned an old image? The scan may be today, but the metadata should relate to the image -- if known -- not the date it was scanned. After all, if you export an edited image the metadata contains the timestamp of when the image was created, not the current date/time.
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  • SFA
    [quote="marchyman" wrote:
    Yes, it is about UNIX time. That's why I knew to check if it was pre 1970 or not. However, there is NOTHING stopping Phase One from handling negative offsets from the epoch which would allow dates going back to 1834. The proof of this is Lightroom and exiftool and others. They handle timestamps before 1970.

    As for those who say such dates are not logical: Have you never scanned an old image? The scan may be today, but the metadata should relate to the image -- if known -- not the date it was scanned. After all, if you export an edited image the metadata contains the timestamp of when the image was created, not the current date/time.


    EXIF is, by intent, a record of when the file was created, not something necessarily related to the content of the image.

    Hence the additional IPTC fields.


    Grant
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  • ericnepean
    Capture One Date Metadata is connected to Date Created in MacOS and to file creation date in the underlying UNIX Operating system.

    This date is fundamental to UNIX to MacOS - it is almost impossible for a user to edit this - only the system can set it, or someone with admin privileges and developer tools. It starts in 1970, when UNIX was born, and indicates when the digital item was created.

    It will be impossible to modify this part of Capture One, given how deep its roots are.

    But Capture One now has a Cultural Heritage version, where users will be dealing with items much older than UNIX.

    It would reasonable to add the IPTC Circa Date Created Metadata field which would be applicable to scanned images and images of physical artworks, like prints, paintings and sculptures.
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  • Robert Farhi
    Thanks Eric for these explanations.
    "Circa Date Created" could be worth to be included in IPTC, indeed.
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  • Marco Hyman
    [quote="Eric Nepean" wrote:

    This date is fundamental to UNIX to MacOS - it is almost impossible for a user to edit this - only the system can set it, or someone with admin privileges and developer tools.


    That is not even close to being true. Any user can modify the date/time of any file they have permission to change. No admin permissions are needed. No developer tools need be used. There are even applications you can download to do the job for you if you find the command line scary.

    I am not asking that Capture One edit any dates. There are plenty of tools that let me do that job. Exiftool will let me set dates in image metadata as well as the UNIX access/modify/create dates. What I want is for Capture One to handle the dates once set.

    As for the intent of EXIF... How the field is being used by photographers trumps, IMHO, the designers intent. There are eleventy seven articles on the web telling people how to modify the date/time. It is often done to fix bad camera times after the fact, i.e. before trying to match images to locations from a GPS track log. Until Capture One lets me filter by date using some other metadata field capture date is all that I have.
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  • Robert Farhi
    [quote="Eric Nepean" wrote:

    This date is fundamental to UNIX to MacOS - it is almost impossible for a user to edit this - only the system can set it, or someone with admin privileges and developer tools. It starts in 1970, when UNIX was born, and indicates when the digital item was created.


    [quote="marchyman" wrote:

    That is not even close to being true. Any user can modify the date/time of any file they have permission to change. No admin permissions are needed. No developer tools need be used. There are even applications you can download to do the job for you if you find the command line scary.


    Oh yes, I remember that I have some scans I made of negative films, and that I assigned as taken in, e.g., July 1951. And they are indeed labelled as July 1951 in Lightroom "Image date" EXIF. On a Mac....
    So, it is just a limitation of Capture One using this time method, as underlined to me by the support in January 2017.
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  • SFA
    [quote="marchyman" wrote:
    [quote="Eric Nepean" wrote:


    As for the intent of EXIF... How the field is being used by photographers trumps, IMHO, the designers intent.


    Possibly not in several professional sphere's of influence. The media for example.

    Or any business that may have controls in place for Historic forensic analysis of files.

    Unix, and other OSs, will of course have to deal with files with bad dates (or even just 'bad dates' in the files where the field is stored as a "Date" format) usually they choose to just default to a date value of 0 rather then going negative.

    But you probably know that already.



    Grant
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  • Marco Hyman
    [quote="SFA" wrote:

    Unix, and other OSs, will of course have to deal with files with bad dates (or even just 'bad dates' in the files where the field is stored as a "Date" format) usually they choose to just default to a date value of 0 rather then going negative.


    Open up a terminal window. cd to some directory where you don't mind creating a dummy file. Enter this command:

    touch -t 191001011200 foo

    Now look at the timestamp of the file foo.


    ls -l foo
    -rw-r--r-- 1 marc staff 0 Jan 1 1910 foo


    macOS has no problem with the "negative" (before Jan 1 1970) dates. Capture One does. I do wish they'd fix that. I'd like to toss Lightroom but I need the ability to search a catalog by date, including dates before 1/1/1970.
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  • ericnepean
    [quote="marchyman" wrote:
    [quote="SFA" wrote:

    Unix, and other OSs, will of course have to deal with files with bad dates (or even just 'bad dates' in the files where the field is stored as a "Date" format) usually they choose to just default to a date value of 0 rather then going negative.


    Open up a terminal window. cd to some directory where you don't mind creating a dummy file. Enter this command:

    touch -t 191001011200 foo

    Now look at the timestamp of the file foo.


    ls -l foo
    -rw-r--r-- 1 marc staff 0 Jan 1 1910 foo


    macOS has no problem with the "negative" (before Jan 1 1970) dates. Capture One does. I do wish they'd fix that. I'd like to toss Lightroom but I need the ability to search a catalog by date, including dates before 1/1/1970.
    Above is not a particularly insightful demonstration, since you can't import a file called foo into Capture One, and all of it's timestamps are identical.

    Full Demonstration

    Find an image file imported imported some months ago to your Mac which is not in your Capture One catalog; perhaps xyz.jpg

    Execute
    touch xyz.jpg
    ls -l xyz.jpg


    Ah yes, that's today's date

    Now import xyz.jpg into Capture One

    Check the the image date in Capture One.

    It's not today's date!

    Now open xyz.jpg Preview and check the image creation date.
    That date matches the date in Capture One.

    stat will show 4 timestamps associated with a file; it is the 4th timestamp which matches the Capture One date and the EXIF creation date - and the touch command won't touch it.
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  • Marco Hyman
    Eric, apparently the reason for my example was not explicitly made; my apologies.

    The example was provided to prove a comment to the effect of "the OS can't handle negative dates" wrong. The OS can indeed handle negative dates, i.e. dates before Jan 1 1970. Capture One can't. This is a limitation in Capture One. Other software that performs DAM functions do not have that limitation.
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  • Michael Naylor
    I've contacted support about this each time an updated trial was released, but PhaseOne aren't interested in fixing this. With thousands of scanned images, all with EXIF dates going back to 1906, my only choice is to stick with Lightroom.
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