James Cameron has slammed the procedure employed by some filmmakers to convert films lensed in 2D to the 3D format.

According to Cameron making a movie in 3D like he filmed Avatar ensures better quality over subsequent conversion.

Cameron said filmmakers should have been pounding on the gates of the studios saying we want to make movies in 3D.

However the Titanic director, 55 pointed out that the appetite for 3D films might soon dip.

The problem is these decisions should be made by filmmakers they shouldn't be made by studios because if it was up to studious they were going to sacrifice quality for lower cost the BBC quoted Cameron as saying.

Cameron has also disclosed plans to convert Titanic into 3D but said he will take his time and not go with a 'slapdash conversion'.