Hi!

It looks like on the colorspace node you did, you only changed the
primaries to ACES but left the Illuminant to D65 ( instead of ACES ).

In which case the  matrix will be:
1.53818 -0.351359 -0.166865 -0.129178 1.01683 0.0953645 -0.0112418
0.0599613 0.880791

Could that be it?

/Håkan



On 20 October 2014 13:05, Simon Björk <[email protected]> wrote:

> 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>
>> >
>> >     _______________________________________________
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>> >
>> >
>> >
>> >
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>>
>> --
>> ben dickson
>> 2D TD | [email protected]
>> rising sun pictures | www.rsp.com.au
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-- 
Håkan Blomdahl
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