I have been supplied some 8bit MXF REC709 files.
The editor has also sent some “.cube” luts and also some ASC_SOP and ASC_SAT values.
Does anyone have any idea how to get either of these to work?
Many thanks
For the LUT, the standard Color Management Node can load .cube files.
For the CDL, there’s a CDL node. Not sure if it can read a file, but it’s just a few values, so you could probably hand enter them.
Hello, thanks for this.
I’ve loaded in the .cube into the 3D LUT color management node.
I can’t find a CDL node or see anything like your second screengrab. Where have they hidden that?
In Matchbox. If you don’t see it there, you may have to check Logik Matchbook.
ah ha! I haven’t looked in matchbox ! THANKS
the ‘Look’ node is also for applying CDL values and can import them from .cdl and .cc files. If you’re conforming from an AAF or EDL that includes CDL values you can also activate the “Convert CDL to Look” button in the format options and it will generate Look timelineFX for all the clips on the sequence.
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But 8bit MXF files in rec709 might be a can of worms… depending on the deliverables of course. Just didn’t seem ideal with a supplied .cube and .cdl
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Thanks for the help and tips everyone !
I Just cant get any of these to look right. I’ll speak with the VFX editor tomorrow
if memory serves the LUTs / .cube files are most likely expecting a log input FYI. (that’s what the DIT on set is building the LUTs on top of) you will need to rack and stack some color mgt transforms with the ‘custom’ node to convert the incoming signal to Log…
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That’s a good call-out. 3D LUTs are always color space dependent and will only look right in the same colorspace they were created in (for creative LUTs). There’s of course colorspace conversion LUTs as well that need to be treated accordingly.
Wouldn’t necessarily assume that they’re built on Log though. Best to ask, or try the obvious and see if it looks right.
The practice of combining colorspace transform and look into a single LUT is common but unfortunate.
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yeah i forgot to add what @allklier mentions - most of our footage comes from Arri Alexa cameras so i’m assuming it originates as Log colorspace.however depending on what camera it was shot on and what you working colorspace is things might be diff. regardless there should be a way to shoe horn any of the major camera flavors into a friendly colorspace for your .cube files.
its usually the ref
in longfrom its very common to have a reference rec709 daily as a target for you to match , the cdl and lut are supposed to go on the exrs (or whatever) you have received
usually the lut is a “showlut” and the cdl is the specific “shotgrade”
usually the lut is made to sit on top of a log encode usually camera native log, but it could be a look lut before a aces view transform as well.
so very often you see
linear->log->cdl-> lut
but there could also be acescg->acescct->cdl->lut-> acesDisplay
it all depends on yhe colorpipeline used
you get used to getting undocumented luts and cdls and its like a puzzle to match the reference without any information. there are hints like metadata in the exrs or whatever but yea ive been there …
with ocio and stuff you can set it up so that each shot has its own shotgrade thats applied to the viewer in each app using ocio, its super nifty but requires some pipeline tooling to pass the shot name to the ocio with system variables - we launch blender, houdini etc with a custom launcher that loads the right ocio config and sets the correct shot specific variable that load the right shotgtade and showlut as loaded into our database.
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@finn - OCIO mailing list is always very busy
What always surprises me about threads like this is the number of people who are receiving CDLs and LUTs without a project workflow guide to specify the colour path and how to use them.
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We usually get a tech specs document outlining the colour pipeline.
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I find it usually depends on where in the chain you are , the further away you are from the responsible colorpipe people the harder it gets .
if you are doing DI you probably talk to the DIT or even DP and design workflows ,
first vfx vendor might get a sheet
3rd in line vfx vendor probably gets nothing 
I just made OCIO configs for everyone when I was doing DI and a clearly laid out sheet , we had proper naming of our LUTs and CDLs or “LMTs”.
But yea i am super good at guessing color pipelines , its like a puzzle, love doing it , so if you have a plate and a dailiy and a random assortment of luts and CDLs, hit me up happy to help
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How to keep Finn busy on Christmas morning…
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like actually i once did it for 3 weeks straight because nobody told us what CDL goes with wich shot and I had to setup like 3 episodes with shotgrade.
best time of my life.
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