Undo edit time

[frlindla]

I have tried to edit the time for some photos because it`s wrong. But I just wanted to change the date, not the time. How can I undo this?
I have tried ctrl+z, but nothing happens.

[frlindla]

Some more information:
The files are stacked files - a cr2-file and a jpg-file. I tried to edit the time when they were collapsed. It seems like the JPGs haven`t changed. So I Wonder how I can do this now. As I said, I tried to undo but nothing happened. At least it seems like most of the JPGs have the right time. Is there a way to let the masters get the same time as the Versions?

[Mario]

How have you "edited" date and time?
Almost all command work on the selected files. If a file is hidden under a stack, it cannot be selected. Expand the stack and select all the files you want to process before you apply the command.

The typical way ti change date or time is via the Metadata Panel. And this changes exactly what you type in. If you change only the time part, only the time will change.
You did not say which command / feature you have used to change the date and time, though.

if you have used Command > Image > Modify EXIF Date & Time, this command works on all selected files and allows you to fix a wrong timestamp written by your camera. This command directly updates the metadata in the file via ExifTool, so there can be no undo.

[frlindla]

So how do you recommend to solve this? How can I get the right time from the Versions to the masters?

[Mario]

New info: You are using file relations and you propagate metadata.

Metadata propagation works on per-tag basis. Since the XMP timestamp tags contain both date and time, you cannot just propagate the time portion from the master to the version.
Just select the version in a File Window and then update the time as needed in the Metadata Panel.

I here assume you are talking about XMP date and time, not EXIF, GPS or legacy date and time data...

[frlindla]

Yes, I want to change the date and time for when the photo was taken, so I Guess I have to choose Date/time original under XMP exif? I am in the browser in the metadata panel. I tried this Field and chose "choose date". I pasted the chosen New time and date into the Field Date/Time original and saved. Then I used the pen to Write back. But why doesn`t the time and date change?

[frlindla]

Or should I use one of the metadata-templates?

[Mario]

You wrote "I pasted...".

You write "XMP exif"? This sounds as you you were trying to modify the EXIF timestamps directly?
Don't do this. These tags will be overwritten by the official XMP "Created Date" and "Date Subject created" during write-back - because of Metadata Working Group compliance.
Just use the two default date & time values displayed under "Core Data" in the "Default" metadata panel layout. These are the proper XMP timestamps and they will be copied into EXIF (and legacy IPTC) during write-back.

If you manipulate EXIF data (or XMP EXIF data directly) make sure you understand the MWG rules so you know which tags are mapped to which tags during write-back.
This does not affect many tags, but date and time for sure, and also description, EXIF copyright notices etc. For all these tags its best to use the standard tags in the "Default" metadata panel layout and IMatch will make sure that the XMP and corresponding XMP, XMP photoshop, XMP IPTCCore and XMP IPTCExt and legacy IPTC tags are updated correctly.

[Mario]

You can also use Metadata Templates. The same restrictions apply. Always update the "official" created and datesubject created tags, don't update EXIF metadata (or XMP EXIF metadata) directly if the tags use MWG compliance mapping. Always use the standard tags also used in the Default Metadata Panel:

XMP::xmp\CreateDate\CreateDate
XMP::photoshop\DateCreated\DateCreated

Yes, metadata is a bitch. Best to let IMatch take care of it.

[frlindla]

Thank you:) So the IPTC Metadata-template can not be used? (under Image : Date Subject Created)

[frlindla]

In the default metadata panel under core data you have "created date" and "date subject created". What is the difference? Which should i choose when I want to change date and time?

How can date and time change in Imatch? I have some photos that have changed date and time. I haven`t changed the date and time, so how can this happen?

[Mario]

The dates and times are all standardized, in the XMP standard.

Date subject created indicates the actual time of the photo, which is not necessarily the time the digital image was created (think: scanning old negatives).
Date created indicates the time the digital file was created.
Digital cameras set usually both to the same time. But both are optional. Software and cameras may set them, or not.
IMatch does not change date and time by itself.  It may use the "last modified date and time on disk" if no other dates and times are available in your files. This may cause the timestamps to change when you re-save a file.

But that is all explained in-depth in the IMatch help so I don't need to repeat that again.
See this help topic: How IMatch uses Date and Time Information

[lbo]

The dates and times are all standardized, in the XMP standard.

Date subject created indicates the actual time of the photo, which is not necessarily the time the digital image was created (think: scanning old negatives).

The descriptions shown by IMatch add another layer of abstraction, although we already have too many different, confusing terms for the same data:

• "Date Subject Created": The name IMatch displays in the metadata panel. I find "subject" misleading.
• XMP::photoshop\DateCreated\DateCreated: The tag it is really mapped to (Note that it doesn't say "subject")
• "specifies when a photo was taken": MWG explanation #1. Likely the clearest one.
• "Creation date of the intellectual content (e.g. the photograph), rather than the creation date of the content being shown": MWG explanation #2, copied from XMP spec part 2, IMO less clear than #1
• "Date/time original": MWG name 1
• "Original Date/Time": MWG name 2. That's bad, standards shall use always the same name.
• "DateTimeOriginal": The related ExifTool composite tag and the related Exif tag name
• "Thema erstellt am": The name IMatch displays in the metadata panel when switched to German.

In my opinion, it is misleading that IMatch adds the word "subject" to the tag description, because In the MWG guidance, "subject" described the object being shown, and photoshop:DateCreated does not just describe the date of the displayed subject! And for the German localisation, "Thema" doesn't describe the tag correctly.

I suggest to change the field descriptions of photoshop:DateCreated (in immbcfg.xml):

"Original Date/Time" doesn't seem bad since it is used in the MWG guidance and close to the Exif tag name. A tooltip "Specifies when a photo was taken" can eliminate ambiguities.

"Aufnahmedatum" might be a good candidate for the German wording.

Suggestions, anyone?

Date created indicates the time the digital file was created.

MWG and EXIF call this field Digitized Date/Time resp. DateTimeDigitized, IPTC DigitalCreationDate/Time, xmp:CreateDate.

I would choose one of these existing wordings instead of inventing a new variant. "Date created" is not clearer than "Creation Date".

A tooltip "Creation date of the digital representation" might be helpful.

Can tooltips be added to existing panel layouts by an IMatch update?

But that is all explained in-depth in the IMatch help so I don't need to repeat that again.
See this help topic: How IMatch uses Date and Time Information

This help page primarily describes how File.DateTime is filled. It could describe in more detail the relationship between and meaning of the Exif, XMP and IPTC tags.

Oliver

[Mario]

IMatch by default uses the tag names as delivered by ExifTool, depending on the user interface language in IMatch if available.

You can change the name displayed in the Metadata Panel to whatever you like. Just edit the Metadata Panel of your choice.
You can also add a description to remind you of what is what if you find that useful.

You can never do it right for every user and hence I made this changeable.
Adobe has changed the names of these fields in their applications several times over the years, and uses different names for the same thing in different products...

I cannot reproduce all that has been written about photo metadata in the IMatch help or the IMatch user interface.
There are entire web sites dedicated to photo metadata, books have been written about photo workflows, metadata management etc.
If "created date" and "date subject created" cause confusion I recommend

Looking at how many related support cases come in, it's not much of a problem for the majority of users.
I don't want to change the names of these tags used for the past 5 years.

[lbo]

IMatch by default uses the tag names as delivered by ExifTool, depending on the user interface language in IMatch if available.

Metadata Panel "1 Default" does not show "the tag names as delivered by ExifTool" as you write but aliases defined in immbcfg.xml.

The wordings of theses aliases differ from ExifTool, XMP standards and MWG guidance.

My yesterday's posting was about providing sensible presets "out of the box" to avoid confusion for new users.

Getting off-topic now, I probably will submit a feature request about improving the default Metadata Panel layout.