I appreciate your reposting this.
Yes, that website is correct.
Someone asked me to elaborate on the clear overhead transparancy part.
Once you cut a value (say all of the black parts) you glue it down on
the clear paper with a copy of the photo underneath- to know where it
goes. Like a puzzle, it can get confusing if you don't pay close
attention to what value you are working on.
Good luck to all and show me your results too!