Reversing the IPP2 Image transform LUTS? Possible?

[Dermot Shane]

REDCine-X makes the same kind of output LUTs that the mentioned ARRI LUT creator makes - only you don't need to go to a website - you just use the RED Tool you already have. The ARRI web site does not provide inverses.

For inverses, at the moment, you'll need to come to me, but we'll look at making them more available once they've been more thoroughly tested.

Graeme

hopefully will never need to, but awesome that you offer to help, a similar thing happened to me a few years ago, VFX done on plates created by an assistant editor with seemingly random values and curves drawn.... then shots extended so i had to somehow match the VFX to the cam orig in the middle of a shot.. did i mention trainwreck? Ended up masking the effects and comping over cam orig back then

best answer is have an adult pull vfx plates -or- handover cam orig with simple/clean debayer settings and avoid the whole mess entirely

 

[Björn Benckert]

hopefully will never need to, but awesome that you offer to help, a similar thing happened to me a few years ago, VFX done on plates created by an assistant editor with seemingly random values and curves drawn.... then shots extended so i had to somehow match the VFX to the cam orig in the middle of a shot.. did i mention trainwreck? Ended up masking the effects and comping over cam orig back then

best answer is have an adult pull vfx plates -or- handover cam orig with simple/clean debayer settings and avoid the whole mess entirely

What do you mean with an adult? Normally VFX should be done linear, thats how CG is created and thats how the compositing tools does their math and transfers. So if you want to comp before grade shit will need to dip into linear.

To comp CG onto of graded footage is simply not the right way to do it. Sure can be done but in comparison its a lot like grading on a color altered baked jpg or such it might work but stuff does not behave correctly .

So would love to know what those adults that you refer to actually do. If using IPP2 and transcode to rec 709 or such then the CG will not blend correctly so then you would need to go from rec 709 to linear which is a double dip... not such a good move. So straight from Red wide gamut RGB to linear and then when comped back to redwide gamut to match the ungraded footage or to rec 709 or such would, to me be the correct way. But not sure how to do it. Graemes white paper explains it but I guess I´m not enough of an adult to understand how to code such lut. So maybe you can explain how its done.

What do you mean with a is a simple clean debayer setting? As to me it needs to be a known or something that is reversable.

 

[Dermot Shane]

hey, i'm just a colorist, not a post sup or vfx sup

i grade a film shot on red (working in Nucoda), wait for VFX to show, when they do they look like ass, and are too short

VFX crew rightly refuse to re-do as they flagged the plates as crap, producer didn't understand or listen
whatca gonna do?
in my case a decade of compositing came in handy, and no the final film didn't look like ass, looked fine but i know more than a few tricks anyway

end game if could have reversed the wacko setting the assist used, would have.. wish the VFX crew had just put down tools until it was sorted rather than doing hundreds of shots on crap plates, that was long before i was hired to grade the film, i had no input into the decisions made, just gotta roll with the flow and get the show out the door on time, past QC and reflecting the vision of the DP and director

easy, peasy on a good day..

 

[Andreas Restle]

Hi Graeme,

I'm in a similar situation to Jason. VFX works was done RED IPP2 footage with "Low Contrast - Very Soft Rec709"applied and rendered out from Resolve. Grading was done on the same IPP2 footage, but with that same LUT applied on top (as in a viewer LUT).
All the VFX work has been done and obviously the grading doesn't match now.

Could you provide me with an inverse LUT?

Thanks a lot

Andreas