A revision is specified by its SHA1 hash.
If you want to see commits for specific files, you have to separate paths with --:
git log oldhash..newhash -- path/to/inspect
does this.
Also note that you are using three dots (...) to specify the range. Usually, you only want two dots.
Three dots might not give the result you’d expect. As the man page for gitrevisions (section SPECIFYING RANGES) says, while
git log a..b
means give me all commits that were made since a, until and including b (or, like the man page puts it “Include commits that are reachable from b but exclude those that are reachable from a”), the three-dot variant
git log a...b
means “Include commits that are reachable from either a or b but exclude those that are reachable from both”, which is a totally different thing.