Thank you! I needed to know the term used to define this kind of effect and now I have it - 'light leaks'. Now I need to find a way to apply this effect post-production. I have never really experimented with film cameras, although I really should. I have discovered a plugin for After Effects and Final Cut Pro called Magic Bullet Suite. Do you know of any other ways to implement this kind of effect in either of those two software packages? I have only just installed these on my machine and I don't really know which I should be using for editing my videos.