Its not illegal to make a backup of a film or DVD that you legally own, nor is it illegal (in my country anyway according to a court ruling) to make a backup of a rental DVD.
As I said, in
MOST countries it
IS a breach of copyright to make a copy of a film on DVD, for whatever purpose. This is not opinion, it is fact - however unfair, unreasonable or perverse it may appear (as it does to me in the context of fair personal use).
There are a few more enlightened jurisdictions - such as yours - where a more reasonable view is taken. Hopefully sense will prevail in time.
SD