James Cameron, director of billion dollar hits such as Titanic and the recent 3D extravaganza Avatar, has dubbed the iPhone an suitable platform for watching his films.
In an interview with US cinema site Collider, Mr Cameron claimed that his movies' lavish effects translate badly to mobile phone screens.
He said: "I don't feel that I'm making movies for iPhones. If someone wants to watch it on an iPhone, I'm not going to stop them, especially if they're paying for it, but I don't recommend it.
"I think it's dumb when you have characters that are so small in the frame that they're not visible."
Other members of Hollywood's film-making A-list have criticised the use of mobile phones for watching movies in the past, including one particularly interesting rant from David Lynch, in which he laid into the iPhone on YouTube.
The directors' ire is, however, unlikely to stop people downloading and paying for film content on their phones, particularly as many titles do not rely on explosions and motion capture technology to entertain the audience.