COLOR SPACE -Tonemapped / Untonemapped...
Posted: Thu Jan 09, 2014 12:30 pm
Hi all !
I made many test with Octane to render a real unclamped image. And, I haven't the solution yet...
I made a simple scene that I rendered in DL+Direct (Camera response : Agfacolor_Futura_II_200CD), and I saved one in tonemapped and the other is untonemapped (the both are saved in exr).
There are 3 images :
Ok, for the moment, there is no problem 
Next, I configured my read node in Nuke to read the file in sRGB :
Image 4 (tonemapped in sRGB) and Image 1 (print screen) are exactly the same.
But first problem : The renderings aren't the same. Image 5 is more luminous than Image 4...
And that's not all : There is no color value upper 1, even on Image 5 which is untonemapped ! => Clamping :/
So, I tried an other solution to convert linear file in sRGB in nuke. I used the Colorspace node :
0k, Image 6 is exactly the same as Image 1.
And Image 7 has no pixel error on the sphere (for example)
Furthermore,the untonemapped image are color value upper 1
!
BUT, The renderings aren't the same. Image 7 is more luminous than Image 6... :/
Finally, I tried a last node in Nuke named "OCIO File Transform" (http://opencolorio.org/index.html). This node reads a file which convert linear files to Agfacolor files (http://code.metager.de/source/xref/blen ... _200.spi1d) :
Images are visually the same with OCIO node and Colorspace node. But the supers whites (untonemapped files) have not the same value...
So my question is : Do you know a way to have exactly the same image Tonemapped and Untonemapped with unclamped value ? I would like Image 1 result with color value upper 1 in the specular... Please
!
Thanks to you !
See ya !
PS : Sorry for my english...
And this is my node graph :
Thanks again !
I made many test with Octane to render a real unclamped image. And, I haven't the solution yet...
I made a simple scene that I rendered in DL+Direct (Camera response : Agfacolor_Futura_II_200CD), and I saved one in tonemapped and the other is untonemapped (the both are saved in exr).
There are 3 images :
- 1-Print Screen of the OctaneRender Viewport (I work with 3dsMax, but I also tried with the standalone, and this is the same problem)
- 2-Tonemapped file read in linear by Nuke
- 3-Untonemapped file read in linear by Nuke
Next, I configured my read node in Nuke to read the file in sRGB :
- 4-Tonemapped file read in sRGB by Nuke
- 5-Untonemapped file read in sRGB by Nuke
But first problem : The renderings aren't the same. Image 5 is more luminous than Image 4...
And that's not all : There is no color value upper 1, even on Image 5 which is untonemapped ! => Clamping :/
So, I tried an other solution to convert linear file in sRGB in nuke. I used the Colorspace node :
- 6-Tonemapped file with colorspace node
- 7-Untonemapped file with colorspace node
And Image 7 has no pixel error on the sphere (for example)
Furthermore,the untonemapped image are color value upper 1
!BUT, The renderings aren't the same. Image 7 is more luminous than Image 6... :/
Finally, I tried a last node in Nuke named "OCIO File Transform" (http://opencolorio.org/index.html). This node reads a file which convert linear files to Agfacolor files (http://code.metager.de/source/xref/blen ... _200.spi1d) :
- 8-Tonemapped file with OCIO node
- 9-Untonemapped file with OCIO node
So my question is : Do you know a way to have exactly the same image Tonemapped and Untonemapped with unclamped value ? I would like Image 1 result with color value upper 1 in the specular... Please
! Thanks to you !
See ya !
PS : Sorry for my english...
And this is my node graph :
- Nuke Node Graph