Darktable 3.0 Exif on export

Thank you @phweyland and @Thomas_Do . What you describe is what I expected, too. But selecting one tag requires a formular. And if there is no variable in the formular, you will get values that are not correct or the value keeps empty.

One example is “Exif.Photo.Aperture” or “Exif.Photo.FNumber”. I can’t find the corresponding variable.

So how do I get the aperture or f-number to the image I want to export? Because of

$(EXIF_ISO)

is a corresponding variable I tried

$(EXIF_EXPOSURE)

and

$(EXIF_APERTURE)

which I found in the preferences for the GUI. But that variables don’t work

Aperture an FNumber are only examples. Theres are other variables missing

Regards,
Marcus