> Can you point to the ACES to sRGB matrix you found? It'll just be the ACES -> XYZ multiplied with an XYZ->sRGB matrix.
You could use a ColorMatrix node to convert from ACES->XYZ, then a second ColorMatrix to go from XYZ->sRGB using the appropriate matrix from, say, http://www.brucelindbloom.com/index.html?Eqn_RGB_XYZ_Matrix.html#WSMatrices > I've been playing with the colorspace node in Nuke to convert an > ACES file into AlexaV3LogC (primaries only). Anyone know if the > matrix used by the colorspace node is correct? Not sure. It might depend how accurate you want to be. If you look here: https://github.com/ampas/aces-dev/tree/master/transforms/ctl/idt/vendorSupplied/arri/alexa ..specifically this file: https://github.com/ampas/aces-dev/blob/master/transforms/ctl/idt/vendorSupplied/arri/alexa/AlexaParameters-2013-Nov-13/Alexa_aces_matrix.txt ..has different matrices for each colour temperature (for when converting from Alexa footage to ACES) More simply, if you just want to do basic conversion from ACES to sRGB gamut, then you could use this code: https://gist.github.com/dbr/24cfd1033c2d59f263e3 (as described above, by calculating the ACES->XYZ matrix then XYZ->your target gamut) On 20/10/14 12:01, Deke Kincaid wrote: > Can you point to the ACES to sRGB matrix you found? The matrices that > are published from the Academy are going from XYZ to ACES and vs versa. > > -- > Deke Kincaid > Creative Specialist > The Foundry > Skype: dekekincaid > Tel: (310) 399 4555 - Mobile: (310) 883 4313 > Web: www.thefoundry.co.uk <http://www.thefoundry.co.uk/> > Email: [email protected] <mailto:[email protected]> > > On Sun, Oct 19, 2014 at 5:18 AM, Simon Björk <[email protected] > <mailto:[email protected]>> wrote: > > I've been playing with the colorspace node in Nuke to convert an > ACES file into AlexaV3LogC (primaries only). Anyone know if the > matrix used by the colorspace node is correct? > > Colorspace matrix (ACES->AlexaV3LogC): > 1.53461874, -0.354506, -0.180112 > -0.128879, 1.02594, 0.102936 > -0.0112158, 0.0604984, 0.950717 > > The reason that I'm unsure is that I've seen a ACES->sRGB matrix on > another mailing list that does not match the values I find in Nuke. > > Best regards, > Simon > > ------------------------------- > Simon Björk > Compositor/TD > > +46 (0)70-2859503 <tel:%2B46%20%280%2970-2859503> > www.bjorkvisuals.com <http://www.bjorkvisuals.com> > > _______________________________________________ > Nuke-users mailing list > [email protected] > <mailto:[email protected]>, > http://forums.thefoundry.co.uk/ > http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users > > > > > _______________________________________________ > Nuke-users mailing list > [email protected], http://forums.thefoundry.co.uk/ > http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users > -- ben dickson 2D TD | [email protected] rising sun pictures | www.rsp.com.au _______________________________________________ Nuke-users mailing list [email protected], http://forums.thefoundry.co.uk/ http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users
