FORUMS: list search recent posts

Issues using Keylight and Advanced spill suppressor with Alexa C-Log footage 32 bpc in After effects 2018 CC

COW Forums : Adobe After Effects

<< PREVIOUS   •   FAQ   •   VIEW ALL   •   PRINT   •   NEXT >>
Alfonso Suárez
Issues using Keylight and Advanced spill suppressor with Alexa C-Log footage 32 bpc in After effects 2018 CC
on Apr 16, 2018 at 12:44:52 pm

Hi all,

I'm working in a project for a TV series doing some screen replacement with Alexa footage. When I have the comp ready, I deliver the file to do color grading. I've tried for the first time a new workflow, but Advanced spill suppressor is not working properly. Let me tell you the steps I'm following.

1. I turn on Color management, and I select HDTV (rec. 709) wich is the final colorspace. I also work in 32 bpc.
2. I import the Alexa footage, and I assign it the profile ARRI LogC3 Wide Color Gamut - EI800 (wich is the one used on set)
3. Do the comp.
4. Render a Quicktime DNxHR 444 10 bits and in the Color Management tab I also select as the output profile: ARRI LogC3 Wide Color Gamut -EI800.

When I try to do some keying and use the advanced spill supressor I find some artifacts. The main problems with keylight come with areas with heavy motion blur.
I suppose it is because I am getting colors up than 1,000 (as you can see in the attached pictures), because when I use Curves (for example) to reduce the exposure everything is working fine.
I wonder if there's a way to work this way. Or maybe I have to do the keying without assigning the profile ans using it as a matte for the footage, but then again I've got the spill problem.

This is the first time I use this workflow. I used to comp everything without worrying about color management, just working with the flat footage giving me by default in After effects when importing.

I'm trying to know if there's a better way of doing things. Any information will be really appreciated.
Thank you so much!!!






Return to posts index

Walter Soyka
Re: Issues using Keylight and Advanced spill suppressor with Alexa C-Log footage 32 bpc in After effects 2018 CC
on Apr 17, 2018 at 3:12:43 pm

[Alfonso Suárez] "1. I turn on Color management, and I select HDTV (rec. 709) wich is the final colorspace... 4. Render a Quicktime DNxHR 444 10 bits and in the Color Management tab I also select as the output profile: ARRI LogC3 Wide Color Gamut -EI800."

If you're inputting ARRI LogC3 Wide Color Gamut -EI800, and if you're outputting ARRI LogC3 Wide Color Gamut -EI800, why work in Rec. 709?


[Alfonso Suárez] "I suppose it is because I am getting colors up than 1,000 (as you can see in the attached pictures), because when I use Curves (for example) to reduce the exposure everything is working fine."

Very likely the case. You might consider reporting this as a bug:
https://www.adobe.com/products/wishform.html

Rather than using Curves and manually adjusting the green channel, you might consider using a Levels effect. Leave the defaults untouched, but set "Clip to Output White" to "On."

Walter Soyka
Designer & Mad Scientist at Keen Live [link]
Motion Graphics, Widescreen Events, Presentation Design, and Consulting
@keenlive [twitter]   |   RenderBreak [blog]   |   Profile [LinkedIn]


Return to posts index

Alfonso Suárez
Re: Issues using Keylight and Advanced spill suppressor with Alexa C-Log footage 32 bpc in After effects 2018 CC
on Apr 23, 2018 at 8:04:28 am

Hi Walter,
thank you for your reply!

[Walter Soyka] "If you're inputting ARRI LogC3 Wide Color Gamut -EI800, and if you're outputting ARRI LogC3 Wide Color Gamut -EI800, why work in Rec. 709? "

I work in Rec. 709 because is the color space of the delivery (TV series). Is that correct or am I doing something wrong?

[Walter Soyka] "Rather than using Curves and manually adjusting the green channel, you might consider using a Levels effect. Leave the defaults untouched, but set "Clip to Output White" to "On.""

I try using Levels and this is what I get. You can see the effect in the pictures before and after applying it. It gets rid of the green but then a blue halo appears. So I then assume I can't use After effects working with 32 bpc and log files? It's a pity!






Return to posts index

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
© 2019 CreativeCOW.net All Rights Reserved
[TOP]