Here's a very confusing puzzle that took a long time to figure out: exiftool -composite:all shows Date/Time Original, while exiftool -composite:datetimeoriginal shows nothing.
$ exiftool -a -G -composite:all c.jpg
[Composite] Date/Time Created : 2018:01:02 03:04:05
[Composite] Image Size : 2057x2969
[Composite] Megapixels : 6.1
[Composite] Shutter Speed : 1/2000
[Composite] Date/Time Original : 2017:01:02 03:04:05.002
$ exiftool -a -G -composite:datetimeoriginal c.jpg
$
$ exiftool -ver
11.54
This is caused by the Composite tag SubSecDateTimeOriginal, whose description is "Date/Time Original". You can see that by using -s:
$ exiftool -a -G -s -composite:all c.jpg
...
[Composite] SubSecDateTimeOriginal : 2017:01:02 03:04:05.002
The tag doesn't follow the convention that the tag name is the description with the punctuation removed.
I think it would be less confusing if SubSecDateTimeOriginal were renamed to DateTimeOriginal, so that -composite:datetimeoriginal would give the expected results in the very common use-case of examining EXIF from camera photos.
According to the Composite Tags page, there are already two other definitions for Composite:DateTimeOriginal, and I don't know how this third would interact with those. But those two other definitions are for use cases that are much less common, I think (for IPTC and ID3).
Thanks for this suggestion. I agree it is confusing, but I wanted to give the tag a different name so that it could be accessed separately from the other tag(s). It is maybe the description that should be changed, but I would wait until more people complain before considering a change like this.
- Phil