Randy: Ocio should help rectify this and it will be included with a future version of Nuke. You can download it here:
http://opencolorio.org/downloads.html I'm not sure if the one for download is precompiled with the Nuke nodes or not. If not it is fairly simple to compile. -deke On Saturday, December 31, 2011, Jonathan Egstad <[email protected]> wrote: > Don't overthink the Read's 'colorspace' conversion - it can only do a 1D lut applied to RGB equally. It's not a colorspace conversion per-se, only a gamma response conversion. > > -jonathan > > > On Dec 31, 2011, at 1:34 PM, Randy Little <[email protected]> wrote: > >> Ok I am calibrating a Camera and light meter. shooting a grey card ( >> a good one that I know is 18%) I take this file red it into anything >> that reads R3d. and in every case but nuke grey is .18xxxxxxx in float >> and 127.xxxxxxx or 128.xxxxxx in 8 bit. huh. in nuke its .21% ok >> weird. Make file in photoshop in sRGB 2.1 make middle grey 50% (cause >> its gamma corrected sRGB) Take that tiff file into Nuke .21 AGAIN. >> WHAT? ok set read node to RAW. MORE WHAT. It reads at .5 as I would >> expect. ok I studied color a little. This sounds like color space >> conversion matrix problem. Yup if you use LAB 50% then all is great. >> But None of my files are LAB and in RGB they are fine. So it seems >> nuke conversion going through LAB remapping RGB 50% to LAB 50% and >> then not accounting for that. But also if I use a Gamma node set to >> .402 I can get in a gradient .18 to be exactly the middle of the >> gradient as well. This in tern doesn't distribute the values linearly >> threw the gradient either at 10% translation I have only 7% >> illumination change from dmax and from dmin 20% translation results in >> 10% change. As expected when using a gamma node on a raw sRGB since >> srgb is a power curve. Just nukes Power curve seems a bit off. >> Is there a reason for this? >> >> >> Randy S. Little >> http://www.rslittle.com >> _______________________________________________ >> Nuke-users mailing list >> [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 >
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