High end VFX workflows and RED colorspaces

[Russell Dodgson]

Hi all,

So first a request, it would be great to have a Workflow discussion forum dedicated to VFX workflows.

So the question i have, and i hope one of the guys at RED are going to able to pitch in, is will there be a point that RED release code values for their LUT's.

Often, in a VFX heavy pipeline, plates need to enter the pipeline in either log or linear. This therefore requires exporting without the gamma curve.

This is all well and good unless the DOP has shot with the specific RED "look" ,achieved by RedGamma etc, in mind. Or even worse, if the client has fallen in love with what they viewed on set. The ideal would be to export plates in log but have Red Gamma LUT's available for viewing and baking in for client deliveries.

I see Arri are doing the same thing with the Alexa (releasing the logC values, as well as having a LUT generator on their website). This proves that they are aware of the importance of LUT's in a post production environment.

It seems that at the moment all of these options are only available through the RED sdk (is that correct) and so users have to wait for their software platforms to catch up before they can take advantage of RED's updates.

It is really frustrating, especially when the red delivers such a great look, that we cannot use this look outside of the .r3d workflow (which is currently useless in a vfx pipeline.

Sorry if this discussion has been around before, it just seems like a simple thing, that could greatly improve high end post workflows.

Obviously in a feature film workflow going to log without the cameras look is no problem as it will have a full DI process, in a commercials environment it is not so simple.

still doesn't change the fact that it's a really good camera though

any thoughts?

thanks

dodger

 

[Graeme Nattress]

Dodger, can you get your name changed to your real name please: http://www.reduser.net/forum/showthread.php?t=32432

REDLine gives you the LUTs that you need thus:
"--advLutRender <int> - Write out lut information to a file in the output directory. Then procede to render the Clip with the pass through gammaCurve
The file will have the same name as the output file with a .lut extension.
1 = Assimilate 16bit LUT
2 = Shake 12bit LUT
3 = CSP 1D (0.0-1.0) [default: Assimilate 16bit LUT]"

For VFX workflows we recommend using REDLogFilm export for grading, and either REDLogFilm linearized in Nuke with the default settings on the Log2Lin node, or an EXR (which will already be linear). The VFX can then match back to graded footage by exporting with Nuke's Lin2Log node (default settings).

Graeme

 

[Russell Dodgson]

Hey,

Sorry havn't been on here in a while, i posted my name.

Thanks loads for the quick response.

So our usual workflow would be REDlog - nuke. Linearise with REDlog curve in nukes read node. Viewing lut in rec709 for commercials.

So it seems you are saying REDlogFilm is very close to the standard 95/685/0.6 settings in the log2lin node. If thats the case i should have looked into it, i automatically assumed you guys were doing something different to that. Goes to show you should never assume anything.

It also seems that you are saying that i can use redline to export a .lut file that maps the different RED gamma curves (including RedGamma2) is that correct.

So in theory i can use that .lut file in nuke to give me a REDgamma viewing lut. Have i understood correctly.

Also when going to a linear exr would you recommend setting the camera space to "cameraRGB" inside of redcine/storm to achieve as close to sensor data as possible or would you export linear with REDcolor2 baked in.

Am i making sense. I guess i am just trying to work out ways of viewing and displaying in as close a way to onset as possible. Most of the footage we are getting in is shot REDcolor/REDgamma, which we want to be able to see in Nuke/Baselight and others.

thanks again

Russ

 

[Graeme Nattress]

REDLogFilm is precise to the standard Nuke Log2Lin settings. It was exactly designed with that workflow in mind, to be able to match back and forth to an EXR.

I'd not use cameraRGB unless you've decided that you want to do your own camera colorimetry analysis and produce appropriate matrices - going with REDcolor/2 makes sense to me.

Graeme

 

[Russell Dodgson]

Excellent.

I certainly don't want to be doing that so REDcolor2 make sense.

It seems that you are providing all the necessary methods of generating lut files that match your gamma curves, it's just not as obvious a method as with the Arri.

thanks again for the time.

Russ