Deke: I was sure I that it was in this (very interesting) thread <https://groups.google.com/forum/#!topic/academyaces/9b4VuqPcOHQ> I read it, but I'm actually unable to find it at the moment. It was not an official matrix.
Ben: Thanks a lot for those links. I will see if I can get your script working. Interesting about the color temperature by the way, I didn't know that. Best regards, Simon ------------------------------- Simon Björk Compositor/TD +46 (0)70-2859503 www.bjorkvisuals.com 2014-10-20 4:44 GMT+02:00 Ben Dickson <[email protected]>: > > 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 >
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