FORUMS: list search recent posts

ASC CDL worflow with the Alexa camera

COW Forums : ARRI

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
Jonathan Holm
ASC CDL worflow with the Alexa camera
on Apr 19, 2011 at 4:59:27 pm

Hello,

I apologize if this feels like a reposted question in this forum. I've searched for answers and I'm still not 100% sure that my workflow will be ok.

In the next week, I will be receiving Apple Prores 4444 files that will be shot on an Alexa camera. The files are going to be delivered on a drive in the .mov format. From what I can tell, they can import and play in Final Cut with no problem.

Along with the .mov files, there will be the following:

ASC CDL

LUT files

I've never dealt with ASC CDL or LUTs in Final Cut Pro.

From what I understand, the ASC CDL, which is the color decision list from the cinematographer, will NOT import into Final Cut Pro. Is that correct? We have an Avid here as well, which I am told can import ASC CDL's, but I'm not sure. Our big issue here is that we have to send the edits to our graphics people early because it is shot on green screen, and the shots need to be color timed beforehand because they are massive renders with heavy graphics.

They are recording arri log C to apple pro res 4:4:4:4.

On the drive, there will be:

cam_a .mov files
LUTs
Screengrabs


I am told that the LUTs are an ASC CDL type made with a Truelight system.


So, here are my questions:

1. Do we need to purchase a separate program to import the ASC CDL, like deVinci or Lustre?

2. Other than the ASC CDL, does my workflow sound correct (i.e. import .mov files into Final Cut, color correct, then send to after effects)?


Thanks in advance for any help you can give me, it is really, really appreciated.

Jonathan


Return to posts index

Michael Kammes
Re: ASC CDL worflow with the Alexa camera
on Apr 21, 2011 at 2:42:56 pm

To get the ball rolling for discussion, here is what I recommend:

FCP and Avid MC currently have no way of natively importing LUTs on ARRI material.

Thus, we need to use a plugin. Nick Shaw has one that works well for FCP, and may solve your problem:

http://forums.creativecow.net/thread/294/217

His plugins use specific LUTs, and one may be close enough for your purpose.

Short of that, you would have to use an online system (a la Baselight. etc) which can accept the LUTS, then export the baked in LUT .mov, and edit with that.

Personally, I would use Nick Shaw's Plugin, edit with the LOGC "look" filter, then perform an online elsewhere and link to the ASC LUTs.

Good Luck!

~Michael



.: michael kammes mpse
.: senior applications editor . post workflow consultant
.: audio specialist . act fcp . acsr
.: michaelkammes.com
.: twitter: @michaelkammes
.: facebook: /mkammes

Hear me pontificate: Speaking Schedule .


Return to posts index

Oliver Peters
Re: ASC CDL worflow with the Alexa camera
on Apr 22, 2011 at 1:16:31 am

You can download Colorista Free from Red Giant, which will let you input CDL values. This would work in FCP.

The reality, though, is that if you mainly need to generate a viable "one light" appearance to the log-c images. This can be done with the FCP color correctors or Media Composer's color correction mode. Both permit real-time playback (unrendered) while editing if you have a beefy machine. This is generally not true of any of the actual LUTs, like the Nick Shaw FCP plug-ins. Those are great, but not accelerated, so you'd have to bake them into the image before editing.

I'm currently doing a large commercial job (ProRes444 in FCP) and I'm only using the FCP color corrector. I just adjusted a good average setting and apply it to clips as I go. Then tweak a bit as needed. The agency folks are perfectly fine with this for the offline. The final color grade will be done out-of-house anyway, so this is really just for client approval of the rough cut.

- Oliver

Oliver Peters Post Production Services, LLC
Orlando, FL
http://www.oliverpeters.com


Return to posts index


Michael Kammes
Re: ASC CDL worflow with the Alexa camera
on Apr 22, 2011 at 2:15:12 am

As always, excellent info, Oliver.

In the past few months, I've noticed a trend with virtually all of the Alexa projects I've consulted on....the almost mandated use of LUTs during offline. Rec709, color filters, etc are just not enough. I can only assume that the level of DPs using the camera are used to a more 'perfect' offline experience. Id be fine with a Rec709 baked into the ProRes, then a color grade on the ARRIRAW during online. I'm also assuming that due to the development of the Red Giant plugin, Nick Shaws development (plus others) many users are seeing this 'mandate' through offline (or editorial) as well.

Its my understanding that the Alexa may have the framework to take 3rd party LUTs, but it obviously has not been implemented....yet. 'Course, we can always hope FCPX or a future version of Media Composer accepts LUTs in real time!

-Michael



.: michael kammes mpse
.: senior applications editor . post workflow consultant
.: audio specialist . act fcp . acsr
.: michaelkammes.com
.: twitter: @michaelkammes
.: facebook: /mkammes

Hear me pontificate: Speaking Schedule .


Return to posts index

Oliver Peters
Re: ASC CDL worflow with the Alexa camera
on Apr 22, 2011 at 11:28:46 am

Yes, I would presume TV show and feature DPs are picky. They have been in my experience. These projects go through more hands and they are concerned about everyone applying their own oddball correction on the image. In my case, these projects are commercials with DPs and clients who know and trust me, including for color correction. These DPs are no less picky, but there's more familiarity with each other.

There are two straight forward, low-cost approaches. The first is to use the Nick Shaw plug-ins and bake these into files that are then used for offline. The second is to dual-record. Go Log-C to the SxS cards in camera and Rec.709 out the SDI port to an external recorder for offline.

OTOH, I also see complaints from DPs (especially on RED jobs), where the in-camera looks are simply used and rendered and then subsequent color correction is done on top of this. In the case of RED, they will often create a look on set as a "suggestion", which isn't intended as the final.

Since I have a long history with post on film-acquired jobs, I view the 'color-correction for editorial' issue as the same as a one-light film transfer. It's just a temporary, neutral grade that isn't intended to be the final look.

However, the issue would be easily resolved if ARRI simply released a set of plug-ins for all the major NLEs that provided a Log-C to 709 conversion. That's what Nick Shaw's do, except that his aren't officially authorized or engineered by ARRI. They are his own curves.

- Oliver

Oliver Peters Post Production Services, LLC
Orlando, FL
http://www.oliverpeters.com


Return to posts index

todd mcmullen
Re: ASC CDL worflow with the Alexa camera
on Apr 24, 2011 at 12:46:23 am

I would also like to point out that while you may feel a DP is picky or concerned who his involved in the look of a show, it is often times that an experienced DP wants to make sure that a non-log look is presented to the director on the monitors while shooting.
When I was shooting film I would have my loader write "print for future employment" on the camera report, sarcastic but got the point across.
Its like showing a work in progress, people will say the get it but they usually don't.
So a simple lut is usually a way to not have to continually explain the look of a log image.

Todd McMullen
Flip Flop Films
Austin
http://www.toddmcmullen.com


Return to posts index


Oliver Peters
Re: ASC CDL worflow with the Alexa camera
on Apr 24, 2011 at 1:02:21 am

[todd mcmullen] " it is often times that an experienced DP wants to make sure that a non-log look is presented to the director on the monitors while shooting."

With the Alexa, that's simply a matter of setting the camera to output with a 709 profile when feeding the monitor.

It's more of a concern about how to properly handle the image in post. Right now there are no efficient ways with most NLEs to apply a consistent LUT. All approaches require that a LUT is baked in or they tax the resources of the NLE. It becomes a trade-off depending on time and budget.

This will continue to be an issue until most NLEs adopt the ability to apply and/or alter source settings on ingest or imported media clips. NLEs have adopted an SDK with RED that has become the starting point, but it needs to become a standard for all NLEs. The same issue applies to Sony's S-log, as well.

- Oliver

Oliver Peters Post Production Services, LLC
Orlando, FL
http://www.oliverpeters.com


Return to posts index

Oliver Peters
Re: ASC CDL worflow with the Alexa camera
on Apr 24, 2011 at 1:12:37 am

PS: The original question was how to use a CDL during editorial. Let me suggest that this is a workflow, which is based on film dailies.

In other words, the Alexa files + CDLs need to go to a color correction session, which can accept the CDL. The Alexa files are then exported as "baked-in" files or are transferred to tape with the applied correction. Then the tapes or "dailies" files go to the editors.

This is an area where Foundry STORM or Pomfort Silverstack will become useful in the near future.

- Oliver

Oliver Peters Post Production Services, LLC
Orlando, FL
http://www.oliverpeters.com


Return to posts index

Jonathan Holm
Re: ASC CDL worflow with the Alexa camera
on Apr 25, 2011 at 1:44:51 am

Thanks a lot guys. Our biggest issue is that we're supposed to finish here, not go to a CC house. They don't have that in their budget for post, sadly. But all of your info has been extremely helpful. Might end up going with the Nick Shaw plugin and just work with that.


Return to posts index


Oliver Peters
Re: ASC CDL worflow with the Alexa camera
on Apr 25, 2011 at 2:04:52 am

[Jonathan Holm] "Might end up going with the Nick Shaw plugin and just work with that."

Sounds like a plan. You might want to review the workflow I described here:

http://digitalfilms.wordpress.com/2010/11/12/arri-alexa-post-part-2/

- Oliver

Oliver Peters Post Production Services, LLC
Orlando, FL
http://www.oliverpeters.com


Return to posts index

todd mcmullen
Re: ASC CDL worflow with the Alexa camera
on Apr 25, 2011 at 2:45:19 am

The one issue I seem to see here is that the Dp used the true light system here to establish a look.
If you by-pass his look with a plug in from someone else you are going to be compromising a look that they might have been going for. It sounds like a communication gap. The Dp was probably under the impression the luts would be recalled and used in the edit. Or maybe he thought there would be a grading session.
Interesting situation indeed.
I just finished shooting a pilot for NBC with the Alexa. I established a look in ny on a bones system but have to grade in la on a davinci. So I will have to have the ny post house send over my dailies lut files from there system that can be read on the la system. Just to have a base to work with. But I also confirmed that I would have a grading session before we started shooting. So I am covered either way and so are the post
I think workflow communication is essential in most digital productions these days.
Best

Todd McMullen
Flip Flop Films
Austin
http://www.toddmcmullen.com


Return to posts index

Oliver Peters
Re: ASC CDL worflow with the Alexa camera
on Apr 25, 2011 at 11:59:43 am

One possible solution is Red Giant Software's new free LUT Buddy. This allows you to read a LUT in certain formats and then apply that in apps like FCP and After Effects. It does this by applying an instance of LUT Buddy as a filter and then reading the LUT profile. I'm not 100% sure whether it can take any LUT or has to be used at the creation end as well, but it's worth a try.

- Oliver

Oliver Peters Post Production Services, LLC
Orlando, FL
http://www.oliverpeters.com


Return to posts index


Jonathan Holm
Re: ASC CDL worflow with the Alexa camera
on Apr 25, 2011 at 5:04:50 pm

Hi guys,

Thanks again for all your help.

I just downloaded the Nick Shaw plugin demo and it looks like it is reading the LUTs properly. Does it automatically read the LUT files that are in the same folder and apply the color correction to the clips? I can't tell if it is reading the LUT file or if the plugin is just doing a general color correction.

Also, is there a technical reason we can't finish with the Shaw plugin? Our post budget does not allow us to go to a big color correction house, and we are doing a lot of after effects work so we need to have the LUTs applied before we send the clips to our graphics guy.


Thank you everyone, you're all a huge help.


Return to posts index

Oliver Peters
Re: ASC CDL worflow with the Alexa camera
on Apr 25, 2011 at 5:47:57 pm

[Jonathan Holm] " Does it automatically read the LUT files that are in the same folder and apply the color correction to the clips?"

I believe these are just default settings. His plug-in uses his own curve values reverse-engineered from ARRI's log-C to 709 corrections.

[Jonathan Holm] "Also, is there a technical reason we can't finish with the Shaw plugin?"

He is processing in 8-bit and therefore considers these for dailies only. 10-bit values would be better. You may get some banding in gradients like skies. OTOH most of your footage will likely look OK.

- Oliver

Oliver Peters Post Production Services, LLC
Orlando, FL
http://www.oliverpeters.com


Return to posts index

Jonathan Holm
Re: ASC CDL worflow with the Alexa camera
on Apr 25, 2011 at 5:55:40 pm

"I believe these are just default settings. His plug-in uses his own curve values reverse-engineered from ARRI's log-C to 709 corrections."

So does that mean it is not reading the LUT file? After I apply the Nick Shaw filter, the color timing looks pretty close to what the DP wanted (he sent us bitmaps of the images with the color timing information). How is it so accurate without actually reading the LUT file?

"He is processing in 8-bit and therefore considers these for dailies only. 10-bit values would be better. You may get some banding in gradients like skies. OTOH most of your footage will likely look OK."

So does that mean the quality of the footage is degraded?


Thanks again for your help.


Return to posts index


Oliver Peters
Re: ASC CDL worflow with the Alexa camera
on Apr 25, 2011 at 6:04:26 pm

[Jonathan Holm] "So does that mean it is not reading the LUT file?"

I don't believe it does. They happen to be the same adjustments.

[Jonathan Holm] "So does that mean the quality of the footage is degraded?"

Technically yes. The difference between 8-bit and 10-bit.

- Oliver

Oliver Peters Post Production Services, LLC
Orlando, FL
http://www.oliverpeters.com


Return to posts index

Jonathan Holm
Re: ASC CDL worflow with the Alexa camera
on Apr 25, 2011 at 6:09:45 pm

Great, thank you. This is not going on the big screen, so I think we'll be fine using 8 bit over 10 bit and making slight adjustments to get the color correction exactly right. Going to download the full Nick Shaw plugin and use that.


Thanks again for all your help everyone!

Jonathan


Return to posts index

Jonathan Holm
Re: ASC CDL worflow with the Alexa camera
on Apr 25, 2011 at 6:36:11 pm

Just FYI I tried the Red Giant plugin as a quick test before buying the Nick Shaw one, and it can't read the cdl format.

Also, responding to Todd's post earlier, I totally agree more communication was necessary. Unfortunately we were told about the specs only a few hours before they shot it so that's why we're dealing with it now. Looks like we may have a workable solution though.


Return to posts index

Oliver Peters
Re: ASC CDL worflow with the Alexa camera
on Apr 25, 2011 at 7:37:22 pm

[Jonathan Holm] "Just FYI I tried the Red Giant plugin as a quick test before buying the Nick Shaw one, and it can't read the cdl format."

Correct. Colorista Free would allow you to manually enter CDL values, but it can't read an external list. LUT Buddy would read a LUT file in one of several color profile formats, like .icc. A CDL is a text file, just like an EDL.

- Oliver

Oliver Peters Post Production Services, LLC
Orlando, FL
http://www.oliverpeters.com


Return to posts index

gary adcock
Re: ASC CDL worflow with the Alexa camera
on Apr 25, 2011 at 9:22:06 pm

[Oliver Peters] "I believe these are just default settings. His plug-in uses his own curve values reverse-engineered from ARRI's log-C to 709 corrections."

That is correct, as would be almost all color correction done in RT within FCP, it is also my understanding that there is a large amount of clipping and clamping in the Shaw filter profile to achieve something close to what a real LUT workflow should be, its not just about the color denisity its about adjusting of the gamma of an image heavily weighted in the shadow areas without clipping the highlights.

I use the GlueTools Arriraw converter that also allows for implementing CDL or other 3D LUTs on import when using an Alexa ProRes file recorded in LogC, it was built as part of the offline/ online processing to use Arriraw but as an aside it does allow for a real LUT to be used within FCP.

gary adcock
Studio37

Post and Production Workflow Consultant
Production and Post Stereographer
Chicago, IL

http://blogs.creativecow.net/24640



Return to posts index

Mike Most
Re: ASC CDL worflow with the Alexa camera
on Apr 25, 2011 at 7:42:55 pm

I would humbly point out that any competent colorist should be able to come up with something that matches your original intent directly from the original LogC file using your dailies as a reference very quickly. Using your original LUT will only tie their hands in terms of both range and ability to come up with a "cleaner" version of what you originally intended. A lot of producers, studio people, and even cameramen seem to think that passing on LUTs to the final colorist is a time saver, but as an experienced colorist, I can honestly tell you that it's not. It's one of those things that sounds good, but is usually thrown out by the colorist in favor of a new correction that implements the original intent, but in a better way. Where LUTs are handy is during editorial and/or visual effects work, so that both the editor and the VFX artist can look at the material through the LUT and know what is intended in the final version. But for final color, it's not nearly as useful as many people seem to think, even when it works.


Return to posts index

john sharaf
Re: ASC CDL worflow with the Alexa camera
on Dec 3, 2012 at 3:03:46 am

Just reading this thread now (many months later) but here are a few pertinent things to wrap it up:

The DP on the shoot went to some effort in convincing production to spend extra time and money for the Truelight SDI box to preview the look that they all intended to carry into the dailies. Post should honor that effort and expense.

At that time (last April) one would have to have processed the dailies outside of their edit platform to burn in the look established by the ASC CDL, most likely by sending it out to a color correction facility (although it would not necessarily be an expensive nor time consuming thing to do).

It is now possible for almost anyone with computer skills to download a free copy of DaVinci and apply an ASC CDL to each clip referanced by TC to process the dailies with the on-set color decisions. It's free, only takes a little time.

Unfortunately the Alexa, with it's importable "Look" tool can only accommodate a 1D not full 3D LUT, so while the gamma, lift and gain will match, the color saturation will not.

ASC CDL is becoming more of an industry standard way of moving the onset looks to post, but it seems that with the Alexa it will always require a little processing. For that matter if they're editing on Avid a transcode to DnXHD is often required too and the LUT can be applied at the same time.

Eventually the ASC CDL will be able to be embedded in each clips metadata and editing platforms will be able to interpret and make the corrections in real time. This is the "Holy Grail" of on-set color management and is still a work in progress.

John Sharaf
IA600 Cinematographer
Alexa Studio/4x3 Plus/EV Owner/Operator
Pacific Palisades, Ca.



Return to posts index

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
© 2017 CreativeCOW.net All Rights Reserved
[TOP]