Film recording methods

[Paul Bruening]

I stumbled into this question on another thread. So, now, I'm curious, how is 30 fps material converted to 24 fps film recordation? Is it by some kind of reverse pull-down math?

 

The reason I ask is because I'm interested in shooting film at 30 fps for eventual output through theatrical digital cinema. Yet, so much of the world still runs movies on film projectors. How much trouble is it to convert that 30 fps DI to 24 fps film records?

[Guest tylerhawes]

It requires pre-processing the footage and can be done with a variety of processes, but the best ones use motion analysis and frame interpolation. Snell & Wilcox, Terranex, etc., make solutions for this (which you'll be looking for a post house that owns it). It can be expensive and, while the best processes can be impressive considering what they're being asked to do, it will invariably create artifacts. Also, the "reality" feel of 30fps will not translate once you've put it into 24fps theatrical format. It will be a little weird.

[Paul Bruening]

Thanks Tyler,

 

Given that digital projection hasn't yet taken over in USA, would you rather shoot 24 fps film, scan 24 fps, convert to 30 fps for digital release, record back to film at 24fps for optical projection or shoot 30 fps film, scan at 30 fps, output for digital at 30 fps and convert to 24 fps in recordation for optical projection? What's a better path, currently? What would be a better path if America goes 95% digital projection?

[Adrian Sierkowski]

I would say 24 all the way will be best especially right the now. I would assume, and I know that's dangerous, this will hold true in the future as well even once we go all digital; as it should, in my opinion, remain the prevalent workflow and therefore, the one I would think more places would be ready to handle. I could be totally wrong on the future; though, I'm still waiting for the hoover boards Back to the Future II promised me...

[Guest tylerhawes]

Given that digital projection hasn't yet taken over in USA... What's a better path, currently?

 

Shoot and post 24fps, convert to 30 only as needed for distribution. Converting 24fps to 30 is easy and looks good, the other way is not and does not.

 

What would be a better path if America goes 95% digital projection?

 

The DCI spec only requires support for 24fps (except stereo 3D, which is 48fps, 24 for each eye). Support for 30fps isn't dealt with in the spec at all. So an all-digital conversion won't eliminate your problem unless a critical mass of digital cinema playback systems implement 30fps on their own, in which case it's not spec-based so I'd worry about compatibility. I'm not familiar enough with all the product offerings to know if Dolby, Doremi, Qube, etc., are offering 30fps support, I only know that it isn't required by the DCI spec.

 

Finally, even if USA is 100% digital, the foreign market cannot be ignored for most films, and there's going to be a lot of film projectors out there for a long time.

Edited November 6, 2008 by tylerhawes