Carl Hernz, chief stereographer at Carmichael3D (Florida, USA) made a strage discovery while digging old film stock looking for movies to convert in 2D: he discovered that "Phantom of the Opera" was shot with two side-by-side cameras, but NOT to produce a 3D film. The setup was done to produce two original copies of all takes. As one set of copies was used for local distribution and the other for international distribution, the fact that both films were "sligthly different" never bothered anybody.

While rarely offering a perfect set of pairs due to film speed and misalignment challenges from things such as camera set-up to the condition of the film as it has come down to us, with some reworking via modern technology, approximately 75% of the original Phantom of the Opera has matching stereo pairs, enough to consider the film natively shot in 3D.

Carl Hernz said : "We had to even 'invent' a manner of matching film rate in some instances to make the stereo sequences match. Add to this that the stereo pairs are sometimes reversed, with one reel that generally consists of the left view to suddenly change to offering the right view and then back (even after right after a title card) and vice versa".

The Phantom movie is documented here ni IMDB.

At a series of previews and Halloween parties and gatherings this week, Carl re-introduced his project. Now known as  Le Fantôme de l'Opéra: restauration du film dans sa version originale stéréoscopique, the project is still on track for cinematic release during 2012, mainly at film festivals.

Since this is not a conversion into 3D but a restoration, this would make The Phantom of the Opera one of the earliest major 3D films ever created.

Read the full explanation of the discovery by Carl Hernz himself on the Camichael3D web site.