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| "SOP" is "Slope, Offset, Power" in ASC CDL speak. We chose different names because many people calculate lift/gamma/gain in different ways. Slope is gain (multiplication). Offset is lift (addition). Power is gamma (y^(1/x)). Saturation is saturation. To reverse it, enter the reciprocal of slope as your "gain." Enter the reciprocal of power as "gamma." And enter the negative of offset as "lift." Enter saturation as the reciprocal of the CDL value. The gain setting should work regardless of the color correction app. The gamma value, however, may need to be entered as a reciprocal. The lift value is the hardest to deal with. Many apps adjust gain along with the lift setting, while the ASC CDL is a pure offset. Or use Color Finesse within AE which can read ASC CDLs directly, so you'd just need to invert the values in the .cdl file, then load it in. With all that said, is the CDL really your "viewing LUT" or is it representation of the color correction that's been done, which is the normal use for a CDL? ----- Bob Currier rcurrier@synthetic-ap.com Synthetic Aperture www.synthetic-ap.com Helping Make Your Work Look Its Best On Thu, Aug 1, 2013 6:41 PM, David Torno <torno@sydefxink.com> wrote: >Curious question to anyone who has done a lot of CDL (Color Descision >List) work. I'm use to using a generic Cineon Log to Lin for viewing and >then doing a reverse process with Cineon Lin to Log for final output. >Not once have I ever gotten a proper LUT on a project in the 13+ years >I've been doing this work. Sad, very sad. Anyways, someone finally has >some CDL values (not an actual LUT file mind you) and I can easily, >manually, input the values into Colorista - Free, but how would I do a >reverse of this properly? I'm assuming this CDL is essentially my >"viewing" LUT and I would need it's opposite to reverse it all back with >VFX applied. Did that make sense? Thanks for any insight. > >What the editor exported for me, is an EDL that contained these lines as >well as other clip data. > >*ASC_SOP (1.0000 1.0000 1.0000)(0.0000 0.0000 0.0000)(1.0000 1.0000 1.0000) >*ASC_SAT 1 > > >The ASC_SOP and ASC_SAT data exists, even though they are default >neutral values. I'm hopeful that he will be able to get the actual CDL >values that he is seeing in AVID. > > >-- >David Torno >Visual Effects Artist and Supervisor >http://www.ghosttownmedia.com >david@ghosttownmedia.com >O: 213.739.2290 >C: 818.391.6060 >------------------------------------------------ >http://www.sydefxink.com (main portfolio) >http://aeioweyou.blogspot.com (vfx tutorials and AE scripts blog) >http://mactex.blogspot.com (free textures blog) > > > >+---End of message---+ >To unsubscribe send any message to <ae-list-off@media-motion.tv> > |
