Imax CEO Rich Gelfond has warned that the ubiquity of 3D means that the feature alone has stopped getting people into the cinemas.
With the stock market taking an increasingly dim view of 3D, Gelfond told Deadline that, as you would expect, 3D movies need to be good movies first if they are to prove a hit.
"When 3D was first introduced the public got really excited," says Imax CEO Rich Gelfond.
"But over time it's going to be on a movie-by-movie basis. In some cases it will work. And in others it won't."
It's not exactly a blinding revelation - and it's a viewpoint that has been put forward before - but it's increasingly important for movie makers to understand that bolting on 3D will not necessarily boost viewing figures.
With the last Harry potter film – Harry Potter and the Deathly Hallows: Part II - and Transformers: Dark of the Moon coming soon, the world will be watching the 3D box office takings.
This follows the reaction to RealD's CEO making light of the poor 3D performance of Kung Fu Panda 2 and the latest Pirates of the Caribbean movie.