I've spent few hours trying to find out how to copy data from "Description" field to "Title" on 26 000 images in one folder but without any success. Could anyone help me to solve this problem?
Did you look at the Copying Examples (https://exiftool.org/exiftool_pod.html#copying_examples) in the application documentation?
The command will look like this:
exiftool "-title<description" DIR
where DIR is the folder name.
- Phil