3D or not 3D?

That’s the question facing a lot of filmmakers as they weigh the extra costs of shooting in 3D or converting 2D footage to 3D against the potential box office upside of a 3D release.

Immortals,” the Tarsem-helmed, vfx-heavy saga that opens Friday, faced no such dilemma. It was planned from the start as a 3D movie. But after shooting a handful of scenes in 3D early on, the producers opted to take the conversion route, both to improve production efficiencies and to manage costs.

They also took steps to avoid some of the pitfalls of the conversion process that have bedeviled earlier films, which were criticized for their headache-inducing images and pop-up-book appearance.

“We did a thorough analysis whether it would be better to shoot in 3D or to convert,” said Tucker Tooley, the film’s exec producer and co-prexy of Relativity Media, which produced and released the pic.

One factor encouraging conversion was Tarsem’s speed as a director. “He’s just go, go, go, and when he’s working fast, he gets a different energy and puts the whole film together in his head,” said longtime collaborator and d.p. Brendan Galvin. “Some say it takes 10% longer to shoot in 3D. I think there’s quite a bit more difference.”

The other reason was financial. “We saved money by shooting in 2D and converting to 3D in post,” said Tooley. The bulk of the conversion was handled by the Mumbai facility of Prime Focus, where stereographer David Stump spent months supervising the work.

“Shooting 3D would have required more cameras and technology, and would have allowed fewer setups per day, with extras waiting around the block for the battle scenes,” said Stump. “It would have run into serious money — a lot more than converting it. We did tests for Tarsem so he could see what it would look like, and he signed off. We committed to giving the characters ‘human volume’ so they wouldn’t look like flat cardboard cutouts, and to achieve roundness in their faces.”

In fact, a small number of “Immortals” scenes were shot in 3D — including material intended for a teaser trailer that ended up being a used in the film itself — but the vast majority of the footage was captured in 2D.

“I’m not saying I wouldn’t shoot 3D,” said Galvin. “I can see situations where that would be better. But on this particular film, with the ingredients we had, it wasn’t the way to go.”

“Immortals,” which cost almost $85 million, shot in 62 days on a soundstage in Montreal using Panavision Genesis digital cameras. “Conversion is a great tool if you start with that in mind,” said Tooley. “It worked because we designed everything for the conversion.”

To further enhance the film’s 3D display, “Immortals” is being made available in a higher-brightness version through technology from Real D and Master Image to compensate for the darkening effect of 3D glasses.

Bookings & Signings

Mirisch Agency signed editors Dan Lebental (“Cowboys & Aliens”) and Neil Mandelberg (Lifetime’s “Girl Fight”) and booked production designers Tom Duffield on Allen Hughes’ “Broken City,” Sean Haworth on Gavin Hood’s “Ender’s Game,” Patrizia Von Brandenstein on David Mamet’s untitled Phil Spector project and Stuart Wurtzel on David Frankel’s “Great Hope Springs”; vfx producers Karen Murphy on Bill Condon’s “Twilight Saga: Breaking Dawn — Part 2” and Eric Robertson on Larry Charles’ “The Dictator”; editors Stuart Baird on Sam Mendes’ “Skyfall,” Conrad Buff on Rupert Sanders’ “Snow White and the Huntsman,” Lisa Churgin on Jason Moore’s “Pitch Perfect,” Kevin Stitt on Christopher McQuarrie’s “One Shot,” Barbara Tulliver on Mamet’s Spector project and Steven Weisberg on “Great Hope Springs.”

Dattner Dispoto booked d.p.’s Claudio Miranda on Joseph Kosinski’s untitled Tom Cruise project, Declan Quinn on Mira Nair’s “The Reluctant Fundamentalist,” Eric Maddison on Jacob Gentry’s “Synchronicity,” Ottar Gudnason on Kaspar Barfoed’s “The Numbers Station,” Trevor Forrest on Menhaj Huda’s “Comedown,” Fernando Arguelles on A&E’s “Breakout Kings,” Malik Sayeed on HBO pilot “Da Brick,” and Mark Williams on HBO’s “Eastbound and Down”; and production designer Eve Stewart on Tom Hooper’s “Les Miserables.”

Innovative Artists booked editors Jeff Canavan on Malik Bader’s “Crush,” Maysie Hoy on Tyler Perry’s “Marriage Counselor,” Jeff Werner on Showtime’s “Shameless” and Kate Healey on AMC’s “The Killing”; line producers Avram “Butch” Kaplan Salim Akil’s “Sparkle,” Daniel Sollinger on Tim Holland’s “Killing Frank” and Kelly Manners on USA’s “Necessary Roughness”; d.p. Keith Dunkerley on David Armstron’g “Pawn”; production designers Nathan Amondson on Ariel Vroman’s “Iceman,” Stefania Cella on Franck Khalfoun’s “Maniac” and Cece de Stefano on Fox’s “Touch.”