I'll agree to being confused. Thanks for being more useful than the other commenter and providing some helpful information.
Here's the definition I'm using, from dictionary.com:
"adj. of or pertaining to a mechanism that represents data by measurement of a continuous physical variable, as voltage or pressure."
It's easy for me to see how a video cassette fit this definition, as it is a record of voltage. I can believe that film also fits the definition but I'm not a chemist. What's the continuous physical variable recorded on film?