When to add EFX?

[Sam Roberts]

When using the various Red post techniques (redcine, crimson, redalert, log and transfer etc) What is the best way to add efx to a shot in post production, both on the FCP timeline and also something a little more complicated in After Effects? Are effects shots handled separately?

 

[John Tissavary]

In a traditional feature film post pipeline, vfx plates are supplied to the vendor after a one-light, and the vendor returns the comp'ed vfx shots prior to the final grade.

So the process, using Scratch (could be RedCine, too, though) is:

1) One-light conversion of vfx shots to DPX, or, in some cases openEXR.

2) Composite vfx, render to DPX or openEXR

3) Import to grading tool (Scratch in my case) for final grade


cheers,

John T.

 

[Taraneh]

Which is best to work with when it comes to VFX, DPX or openEXR?

 

[Nick Gallegos]

That really depends on the needs of the VFX house (i.e. their platform). Some prefer DPX, some prefer OpenEXR. Some even like working with TIFF or TGA. The last VFX house I worked with requested TIFF, so that's what he got.

 

[chocblu]

I would also like to know the benefits vs badness of DPX and openEXR from a purely technical standpoint. Are they roughly similar?

 

[eskatonia]

DPX is used for transferring film scans, or now R3D plates. It's uncompressed 10 bit log color.

OpenEXR is usually used for rendered 3D elements or other intermediate stages during post production. It supports both lossy and lossless compression types and can store either 16 bit half float color or 32 bit float color.

It's common on a large scale VFX pipelines for the film scans to be supplied DPX and all the elements used internally by the post house to be rendered to OpenEXR format, then they supply finished composites as DPX files back for grading.

More than you ever wanted to know on OpenEXR:
http://www.openexr.com/TechnicalIntroduction.pdf

 

[Taraneh]

It's common on a large scale VFX pipelines for the film scans to be supplied DPX and all the elements used internally by the post house to be rendered to OpenEXR format, then they supply finished composites as DPX files back for grading.

Is that because OpenEXR has a higher dynamic range/data? I've heard that when comparing the same frame exported in DPX and OpenEXR you hardly see any difference. If so, why work with OpenEXR first and then finish with DPX instead of using DPX all the way?

 

[Charles Angus]

Because your software works better with it?

Because its 32 bit? 16 bit isn't perceptually different from 10 bit log, but 32 bit allows much more room for adjustment (assuming the original has 32 bits, like film, otherwise (like with HD, RED) you're just wasting space.

 

[Uli Plank]

Even if some folks here don't like the cow, here's a pretty informative article:
Go there and look for an article from Pete O'Connell on Cineon format.

DPX is always good enoug for R3D-footage, since 12 bit linear translates perfectly into 10 bit log. But in the VFX pipeline, other formats are sometimes appreciated.

 

[Taraneh]

Your link doesn't seem to work...

 

[Uli Plank]

Yeah, cows are hated around here, can't post it. I edited in the necessary info.