Welcome to our community

Be a part of something great, join today!

Log in
  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

grade first then VFX, or VFX on Redlogfilm/R3D, then grade?

N

nigelsmith

Well-known member
Joined
Nov 19, 2007
Messages
287
Reaction score
0
Points
0
Location
London
Hi
I appreciate any input on a workflow question.
If you have shots going out for VFX [eg After Effects], would you export a redlogfilm gamma file, or use R3D, then grade the shots after return.
Or would you do a grade on the shots first, then export for VFX and rely on them to preserve the colour grade in the shots they return?

Is compositing easier with graded shots?

thanks
Nigel
 
If VFX on redlog film, you need to have a lin2log and log2lin lut. As you dont want to do your VFX work in log. And when you do that process you need to make sure you do not clip or crush.


So if you got redlog film, apply a log to lin conversion and make your effects to taste then apply the reverse log2lin lut and deliver to grade.

And it makes sense to stay in 16bit float or at least 12bit during the VFX as that gives more room for converting without artefacts, and banding or other stuff on the vex work showing up in the grade.
 
PatrickFaith said:
i dont think this conflicts with what is said, but often the digital intermediary supervisor (DI), makes sure the iso and kelvin are set appopriatly before vfx (often this person is called a colorist, but they are not doing what is called the primary or secondary grade).
Click to expand...

Yes the process of going to redlog film locks all the meta data. iso should be adjusted and VB but the rest I would leave as default as its better to adjust after the VFX is applied, since that gives a "more linear" image which is quite close to what the CG will be rendered in. So DP, DIT, DI supervisor or Colourist or who ever feels entitled to know what iso and white balance is preferred before the grade is done should adjust it before burning out the files as redlogfilm. Normally I would say thats the DP´s Job or who ever works for him, the DIT or the DI supervisor. But to me it´s kind of a DOP thing to decide.
 
I've had to work on films where VFX was done after the grading. It's never a good idea because then the grade is locked. Maybe that's alright for some types of content (commercials?) where you'll never return to a project, but it's definitely not a good idea for narrative work.

I've had issues with giving VFX artists actual camera raw media. It is best to bake any metadata in the log media via transcode from your grading application. For short films and low budget features, ProRes4444 is a good interchange format for 1080 and 2K work as it's 12bit and the generational loss of quality from transcoding is minimal. Otherwise 10bit DPX or 16bit .tiff image sequences are standard.

I've also had material that was Redlog returned to me as linear, but applying the linear to cineon log look up table in Resolve sorted this. I gave these clips with the lin to log LUT baked in back to the colourist (Baselight) and he said they were identical to the original Red Dragon footage. I'm not sure why he didn't do the linear to log conversion himself, but I suspect there were some crossed wires at work there in terms of project management, so I should imagine it's possible with Baselight as well.
 
Björn Benckert said:
Yes the process of going to redlog film locks all the meta data. iso should be adjusted and VB but the rest I would leave as default as its better to adjust after the VFX is applied, since that gives a "more linear" image which is quite close to what the CG will be rendered in. So DP, DIT, DI supervisor or Colourist or who ever feels entitled to know what iso and white balance is preferred before the grade is done should adjust it before burning out the files as redlogfilm. Normally I would say thats the DP´s Job or who ever works for him, the DIT or the DI supervisor. But to me it´s kind of a DOP thing to decide.
Click to expand...
How you approach it Björn, if a film was shot at 800 do you grade at 800? DoPs are rarely present when I grade, so unless I see a reason to in the footage itself, I typically stick to Resolve's project defaults for ISO and Kelvin.
 
Will Steer said:
How you approach it Björn, if a film was shot at 800 do you grade at 800? DoPs are rarely present when I grade, so unless I see a reason to in the footage itself, I typically stick to Resolve's project defaults for ISO and Kelvin.
Click to expand...
I always request that I get a copy of the rough cut so I have a general idea as to what the crew saw in dailies and what the director and editor saw every day during cutting. At least we can use that general look as a starting point for color, and then move from there for the final.

I do generally use the ISO and color temp settings from the shoot, unless they just subjectively look bad to me. In some cases, I've seen people shoot at 5400° K when the lighting was actually at 3200°, and for that you ideally do need to manually shift color temperature.
 
It´s different from one project to the next, some DoPs work close to their DIT´s and adjust meta data carefully before material is transcoded to proxies, copied to dub discs, etc and they adjust color temp, iso and so on. Good practice I think. Others just see their job done when proper exposure / raw is captured and let the rest be dealt with down stream from them, works well for some, but less control for the DP no doubt.

I work normally from the raw files and then I can bring in one copy of the edit with camera/RCXP settings for the clips and keep it for refernece. Then I make a duplicate of that edit and remove curves and pretty much every setting except white balance and iso and apply redlogfilm. Then I work form that edit and use log 2 lin before I do something to a shot and lin2log when Im done.

the above gives me an edit with redlog material with effects applied that can be forwarded to grading.

Now, if some iso or white balance is really off then I can adjust those and if the material is crunch or clipping I adjust for that also, as if not the lin2log/log2lin process can be destructive if not.

And normally I work in 12 bit I think 10 bit redlog is a bit tight when thats graded you kind of have a 8 bit image, so staying at 12 bit in redlog that gives room for landing the final colours somewhere around 10bit, 12bit decrease the risk of getting banding in gradients and such.

Then on a lot of project, like the one I current work on. I start the VFX work with raw files with my linear setup described above. As we start early right after shoot and work in parallel with editing, long before the grade takes place. Then later when the grade is done, from a copy of the native source files that is wired to me, I implement those clips into my comp trees, but only for the front layers so all the key inline layers etc are actually pulled from the native source and are referring to the ungraded material affect the graded clips. Long story short, it makes it possible for us to start early and not redo much when the grade is done.
 
Well, trying to shoehorn every VFX situation into one solution is a sure fire recipe for disaster.
Yeah, using proper LUTs for compositing and deliverables, pre-grading material is great idea too, keeping it as a float is another. BUT, you're still locking yourself into a grading decision by someone in a chain- colorist, editor, VFX artist.
How about not doing any of that?
First of all, I sincerely hope, that users will realize, that RAW and VFX don't mix well. At some point early on in the process you WILL lose metadata. So, why fight it? Embrace it and use it to your advantage.
And this is how FilmLight/ Foundry designed their VFX/grading workflow.
1. Nuke VFX artist gets pre-graded shot by a professional colorist in an EXR form. Along with it, VFX artist receives BLG (Baselight Grade) file. It gets imported into Nuke and immediately the shot is set into correct color space, gamma etc. No LUTs, only transforms. BLE even accommodates the sRGB color space for the standard monitor, that many VFX artists use. In other words, VFX artist sees EXACTLY the same graded image, as what colorist intended. And the best part? It's all LIVE. VFX artist can open BLE plugin for Nuke and all grades from Baselight opens up, including color science, tracking, all layers, mattes, keys... everything.
2. VFX artist does his/her thing, incorporating the work into a shot, while still being able to adjust the grade using BLE. Artist then, again, exports the shot as EXR along with new BLG. That EXR now incorporates all standard VFX layers, including mattes.
3. The shot now is brought back into Baselight for a final grade. Again, the shot is completely recreated in Baselight with all EXR layers and all grade changes, that were done by VFX artist. And guess what? The shot is still LIVE. Colorist now has full compliment of Baselight grading tools, utilizing all EXR mattes, so grading is pretty normal.
But the most important thing, nothing ever get's baked in until the very end. One set of metadata is replaced by another and that metadata travels all the way thought the chain. Pretty elegant IMHO.
Anyway, as I said at the beginning, not every situation is the same, so if you're using Resolve and After Effects, or Flame... Well, I'm sorry, you'll need to do something else with lots of LUTs, having good line of communication and hopefully someone at the helm, who knows what to do...
Here is the video demo of the BLG concept:
https://vimeo.com/142230421
 
jake blackstone said:
Well, trying to shoehorn every VFX situation into one solution is a sure fire recipe for disaster.
Yeah, using proper LUTs for compositing and deliverables, pre-grading material is great idea too, keeping it as a float is another. BUT, you're still locking yourself into a grading decision by someone in a chain- colorist, editor, VFX artist.
How about not doing any of that?
First of all, I sincerely hope, that users will realize, that RAW and VFX don't mix well. At some point early on in the process you WILL lose metadata. So, why fight it? Embrace it and use it to your advantage.
And this is how FilmLight/ Foundry designed their VFX/grading workflow.
1. Nuke VFX artist gets pre-graded shot by a professional colorist in an EXR form. Along with it, VFX artist receives BLG (Baselight Grade) file. It gets imported into Nuke and immediately the shot is set into correct color space, gamma etc. No LUTs, only transforms. BLE even accommodates the sRGB color space for the standard monitor, that many VFX artists use. In other words, VFX artist sees EXACTLY the same graded image, as what colorist intended. And the best part? It's all LIVE. VFX artist can open BLE plugin for Nuke and all grades from Baselight opens up, including color science, tracking, all layers, mattes, keys... everything.
2. VFX artist does his/her thing, incorporating the work into a shot, while still being able to adjust the grade using BLE. Artist then, again, exports the shot as EXR along with new BLG. That EXR now incorporates all standard VFX layers, including mattes.
3. The shot now is brought back into Baselight for a final grade. Again, the shot is completely recreated in Baselight with all EXR layers and all grade changes, that were done by VFX artist. And guess what? The shot is still LIVE. Colorist now has full compliment of Baselight grading tools, utilizing all EXR mattes, so grading is pretty normal.
But the most important thing, nothing ever get's baked in until the very end. One set of metadata is replaced by another and that metadata travels all the way thought the chain. Pretty elegant IMHO.
Anyway, as I said at the beginning, not every situation is the same, so if you're using Resolve and After Effects, or Flame... Well, I'm sorry, you'll need to do something else with lots of LUTs, having good line of communication and hopefully someone at the helm, who knows what to do...
Here is the video demo of the BLG concept:
https://vimeo.com/142230421
Click to expand...
Back and forth on EXR is the way to go. I was having a ton of problems having vfx make coloring decisions by applying grading matte's and making decisions to compress things into dpx, now with vfx sending exr (DWB) to grading things are working out much cleaner. I do wish davinci had a better workflow of doing exr layers though, but 12 does support DWB. Also EXR DWB reduces all the file sizes, so it's not this huge ordeal of going exr all over the place now.
 
PatrickFaith said:
Back and forth on EXR is the way to go. I was having a ton of problems having vfx make coloring decisions by applying grading matte's and making decisions to compress things into dpx, now with vfx sending exr (DWB) to grading things are working out much cleaner. I do wish davinci had a better workflow of doing exr layers though, but 12 does support DWB. Also EXR DWB reduces all the file sizes, so it's not this huge ordeal of going exr all over the place now.
Click to expand...

In that case, you still stuck with multiple LUTs and baked in grades, even if Resolve could deal with multiple mattes in EXR, which it can't...
 
jake blackstone said:
In that case, you still stuck with multiple LUTs and baked in grades, even if Resolve could deal with multiple mattes in EXR, which it can't...
Click to expand...
Agreed, I did try to get nuke studio integrated with baselight back in 2014/2015, was very nice but just was too early in the development process for my current production. I will for sure try doing exactly as you mentioned once nuke studio 10 comes out.
 
jake blackstone said:
And this is how FilmLight/ Foundry designed their VFX/grading workflow.
Click to expand...
That's great if the facilities involved are using FilmLight and Nuke. What has happened with me is that I wind up on projects where there's four or five different VFX companies all running around in different directions, each sending back wildly different looks for different sequences in different parts of the film. Bad decisions get made, particularly in cases of little time and low budgets.

What I generally would rather do is send out a temp grade that's about 75% of the way there with DPX files or ProRes 444 (depending again on time and budget), let the VFX people do their thing, then swap out the files and do a final grade on it. This workflow can work very well.

A temp grade exported as a LUT can also work, and I've done that in some instances, going back 12-13 years. There's lots and lots of different ways to approach this workflow.

I would advise the o.p. to do two things:

1) hire an experienced post supervisor who knows VFX and can deal with file management and keeping the look consistent

and/or 2) read the book The VES Handbook of Visual Effects: Industry Standard VFX Practices and Procedures, which goes through several different workflows that are practical with a lot of different projects.

Note that there are some fairly huge big-budget action films that routinely convert everything to DPX and just deal with the entire show as DPX sequences. Raw goes out the window in this case, but they're fairly dilligent in keeping the debayered files neutral in terms of exposure and color. I think the shows look fine and -- in general -- good colorists will have no problem getting the image to where it needs to be.
 
Thanks to everybody for the advice and info, and Marc for the book recommendation :hurray:
It's great to hear how professionals are dealing with this issue in the industry.
It also helps me understand how to implement best practice where compatible within our UK University [cash poor] facilities.
Nigel
 
In the old days, a lab colorist did a one-light on the 35mm before something was to go into VFX, Grading or even offline editing :tongue_smilie:
Maybe we can learn from the old days.
 
I think it depends on the type of VFX. For most touch up, removing things or costmetic VFX I like grading first, then sending my Prores4444 to After Effects or whatever. If it's something more involved, I do a simple pregrade, export that to AE and bring finals into my master grade session later. But generally, I grade everything first, and then export shots at various stages of grading begfore sending to VFX and making a final grade pass once everything is done.

There is no right answer here. Depends on the project, the shot, and how the team wants to approach it.
 
Christoffer Glans said:
In the old days, a lab colorist did a one-light on the 35mm before something was to go into VFX, Grading or even offline editing :tongue_smilie:
Maybe we can learn from the old days.
Click to expand...

One light... not as good as the good old, best light. :)

Jarek Zabczynski said:
I think it depends on the type of VFX. For most touch up, removing things or costmetic VFX I like grading first, then sending my Prores4444 to After Effects or whatever. If it's something more involved, I do a simple pregrade, export that to AE and bring finals into my master grade session later. But generally, I grade everything first, and then export shots at various stages of grading begfore sending to VFX and making a final grade pass once everything is done.

There is no right answer here. Depends on the project, the shot, and how the team wants to approach it.
Click to expand...

Agree.
 
You must log in or register to reply here.
Back
Top