Thanks Phil! Exactly what I needed.
I tried this:
exiftool -P -d '%Y-%m-%d %H.%M.%S' \
'-filename<${DateTimeOriginal}_${Make;}.%e' \
'-filename<${CreateDate}_${Make;}_${Model;}.%e' \
'-filename<${DateTimeOriginal}_${Make;}_${Model;}.%e' \
$@
Is it correct that if all tags are available a file will get renamed three times?
I need to run this on about 20,000+ files. Is there a way I can speed things up a bit? e.g. by using -if? so that if DateTimeOriginal, Make and Model are all available, only the last line will be executed and the file will only get renamed once?