Phil, I am using a bash script to change the filenames. I can't tell you in a few sentences, which conditions result in which filename. Assume I need a unique number, which is yyyymmddhhmmss(+sequencenumber, if there was a rapid sequence). So yes, I am renaming the files according to the date/time but I can't do it with exiftool, the conditions are too complex. Now i am modifying my script for future photos, where the original filename of the camera still exists. This could help me with my problem, but I don't like it very much to modify an original file, which would be necessary with my workflow then.
I like to write the "number-part" in the ImageNumber-filed, but this doesn't work. I use Exiftool 6.95 and executed