A collection of over 3,000 hours of television news and cinema newsreels taken from the ITN/Reuters archive can be accessed from a Brunel Library database. Log in to the Library and then go to 'Databases' and select the source 'Film and TV.' It will allow you to download segments or entire videos.
In addition, you are allowed to use any BBC, ITV or C4 news footage (but not Sky) as long as appropriate attribution is given. You can either use material you have recorded off-air or use an off-air recording backup service to obtain news items on a specific topic you have identified and know the date of (e.g. if you find an item on YouTube and know the broadcast details). Topics within ITN and C4 news can be searched and previewed via the ITN Source website (free registration required).
