James Cameron has criticised bosses behind the Harry Potter franchise for attempting to convert the latest movie into 3D and then failing to complete the task.
The Avatar director is an outspoken advocate of the new technology, but insists the format only works if it is properly managed.
Cameron claims film chiefs compromise on quality by converting movies into 3D at the last minute, and he's adamant Potter bosses should never have attempted to change Harry Potter and the Deathly Hallows: Part 1 ahead of its release this month (Nov10).
He says, "You see another stumble with the most recent Harry Potter movie from the same studio as (Clash of the Titans) making the same mistake - except really getting spanked for it now because they didn't get the film done.
"They announced it in 3D - threw a bunch of money trying to convert it to 3D in post-production and it simply didn't work. They just didn't get it done."
The second installment of the final Harry Potter movie will be shown in 3D when it hits cinemas next year (11).