Skip to main content
K
KeyframeLLC
Participant
April 19, 2022
Question

Some VFX not converting back to LOG with the rest of the export

  • April 19, 2022
  • 2 replies
  • 221 views

I am working on an action film. It was shot on a Blackmagic URSA, and I am receiving LOG .dpx files for the action scenes from the editor (using Premiere). My workflow is to interpret the footage (to Universal Camera Film Printing Density), add a LUT, then apply my effects assets to composite. (This includes muzzle flashes, blood spatter, debris hits, etc.) Then on export, I made a preset that exports my sequence out to ProRes4444, and color management set to the UCFPD setting. (I'm required to turn in LOG deliveries for the colorist.)  This has worked great until I had scenes with blood.

My export appears to be LOG in every way except my blood FX stay linear. The muzzle flashes, debris, dust, etc. all appear like the original footage. Everything except the blood. It stands out ridiculously. I've bounced around hundreds of threads, videos and manuals, and I can't seem to solve this issue. I hope someone here can assist!

I have to admit that this is the first time I've worked with the requirement for LOG exports, and I only barely understand color spaces. I basically followed directions I found on ProVideoCoalition by Chris Zwar. BTW, the blood assets and the other assets all have the same Rec709 color profile in the Projects panel. So I don't understand why only the blood isn't flattening like the rest. I've attached some examples of what is happening.

This topic has been closed for replies.

2 replies

Mylenium
Mylenium
Legend
April 19, 2022

ProRes is one of the formats using hardware accelerated decoding and if it doesn't respond to blending mode changes, there's a good chance something is not right with that and it also evades the color management pipeline. As a test, try to convert one of the hits to anotehr format like a TIFF sequence or such. Heck, even downconverting to 422 may already fix it.

 

Mylenium

Mylenium
Mylenium
Legend
April 19, 2022

Without screenshots of your timeline and exact info on the nature of your blood splats plus render settings and such we can't tell you much. On a hunch I would have to guess that those are PNGs from soem action pack and then one of the many bugs associated with the file format might bite you, but of course it could be a million other things just as well.

 

Mylenium

K
KeyframeLLCAuthor
Participant
April 19, 2022

Thanks for responding. All the assets I'm using in this sequence are ProRes4444 .mov's with an alpha channel. They all use varied transfer modes (Multiply, Overlay, Add, etc.), which doesn't seem to affect them looking LOG or not. The blood assets don't; everything else does, regardless of which mode is being used. Yet they are the same file types and sometimes have the same transfer modes as other assets. If there isn't a specific answer to this issue, I can keep tinkering. I'm also open to recommendations to specific articles, people, or videos that go into delivering log composites with FX if anyone knows of any. I've attached a sample timeline & export settings for you.

Terms & ConditionsAccessibility statement
Using the community Terms of use Privacy Cookie preferences Do not sell or share my personal information ad choicesAdChoices