“The Wizard of Oz,” originally released by MGM in 1939, will make its 3D debut in celebration of the film’s 75th anniversary. Prime Focus World developed a stereo conversion process to convert the classic film into modern 3D, while honoring the original, now part of the classic Warner Bros. library. The process, which took 14 months to complete and involved 1,300 staffers, was especially challenging due to the amount of detail in the original. The 3D version will have a run in IMAX theaters and be made available on Blu-ray next month.

Prime Focus World was the sole partner for the 3D conversion, which started with the restored and digitally re-mastered reels.

“Warner Bros. went all the way back to the film’s original Technicolor camera negative, stored for many years at the George Eastman House, and performed a full photo-chemical restoration before scanning the negative at 4K and digitally restoring the picture,” reports AWN. “The film had never before been seen at such a high resolution.”

PFW used its proprietary View-D 3D conversion process for the update, which will be exclusively shown in IMAX theaters beginning on September 20th, reports StudioDaily. The process was also used on films such as “Star Wars: Episode One — The Phantom Menace,” “Transformers: Dark of the Moon,” “Shrek 3D,” and others.

“Everybody was a little apprehensive about the idea of putting our hands on such a classic film,” said Chris Del Conte, Prime Focus’ VP of business development in Los Angeles.

The initial conversion process involved several challenges as to which scenes and segments to convert. But as the View-D production group determined the correct natural depth for all scenes, they began using 3D more rigorously.

“Once you had control, you could make better creative decisions,” said Justin Jones, View-D supervisor in Vancouver. “For example, you could make the witch more uncomfortable to viewers when she’s on screen. Once we had her in depth, we pulled her chin and nose out more than we would have normally.”

“A lot of the design work happens at the very beginning of the process,” Jones noted. “Once the elements are isolated, we have a stage where we place everything in depth, working out the overall environment — the set, basically — and then giving everything the proper volume and sculpting.”

One of the more challenging aspects to the conversion process involved the scenes featuring the dancing Munchkins with 50 to 100 extras and detailed set designs. Accuracy was necessary, especially in close-ups of characters like Dorothy and the Cowardly Lion.

“We had to be very accurate with the sculpting,” Jones said. “We don’t do any automated processes. The more you automate 3D, the worse it looks. So we really put a lot of focus on character sculpting — making sure it’s accurate and that you’re getting the same detail you would if you shot it.”

Animation World Network has posted an interesting 4-minute video about the 3D conversion process. An equally compelling 12-minute video on the restoration process is available on the Prime Focus site.