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Spotted this on the corona render development blog...
I just ran a test myself in VRay with the same setup, and got results like the sRGB image. In darker scenes that I've had to produce I've sometimes run into issues where certain materials/colours appear a lot darker than I'd have expected, so would it be possible/reasonable to impliment a wide gamut colour space for VRay's calculations behind the scenes? It would make lighting a scene that bit more intuitive and ultimately more realistic.
Internal Color Space is now WIDE RGB
Why?
Corona Renderer was previously using the XYZ color space, as opposed to the sRGB color space used by most renderers. There are several reasons why using wide-gamut color space improves rendering, even though the final rendered image is converted back to sRGB.
The most important is that input material colors are interpreted differently, in much more plausible way. We all know using pure white (RGB 255 255 255) or pure black (RGB 0 0 0) colors is bad (one makes the render times skyrocket, other creates “black holes” in the image. No real object is totally white or black). An sRGB renderer actually faces these same problems every time a color with either 0 or 255 in red, green, or blue is used (for example, pure red, RGB 255 0 0). This means that using such materials will increase render times, and can also create entirely black objects when differently colored light is used.
When using wide gamut color spaces, all color components are converted to not so extreme values internally. This “magic trick” causes the result to look identical under normal, white-ish lighting, but much more plausible when colored lighting is involved.
A secondary effect is that certain phenomena, like low kelvin temperature emission, or physical sun/sky models at sunset, that are out of sRGB gamut, can be easily simulated with wide gamut spaces.
Although the XYZ color space gave good results according to our empirical testing, using it was not theoretically correct, because the color space is not closed under multiplication (meaning it can produce non-existent colors). That’s why we have decided to switch to Wide gamut RGB, which does the job equally as well, is theoretically correct, and slightly more predictable.
Look at the examples below:
[img=http://corona-renderer.com/blog/wp-content/uploads/2014/03/colorspace-1024x184.jpg[/img]
Why?
Corona Renderer was previously using the XYZ color space, as opposed to the sRGB color space used by most renderers. There are several reasons why using wide-gamut color space improves rendering, even though the final rendered image is converted back to sRGB.
The most important is that input material colors are interpreted differently, in much more plausible way. We all know using pure white (RGB 255 255 255) or pure black (RGB 0 0 0) colors is bad (one makes the render times skyrocket, other creates “black holes” in the image. No real object is totally white or black). An sRGB renderer actually faces these same problems every time a color with either 0 or 255 in red, green, or blue is used (for example, pure red, RGB 255 0 0). This means that using such materials will increase render times, and can also create entirely black objects when differently colored light is used.
When using wide gamut color spaces, all color components are converted to not so extreme values internally. This “magic trick” causes the result to look identical under normal, white-ish lighting, but much more plausible when colored lighting is involved.
A secondary effect is that certain phenomena, like low kelvin temperature emission, or physical sun/sky models at sunset, that are out of sRGB gamut, can be easily simulated with wide gamut spaces.
Although the XYZ color space gave good results according to our empirical testing, using it was not theoretically correct, because the color space is not closed under multiplication (meaning it can produce non-existent colors). That’s why we have decided to switch to Wide gamut RGB, which does the job equally as well, is theoretically correct, and slightly more predictable.
Look at the examples below:
[img=http://corona-renderer.com/blog/wp-content/uploads/2014/03/colorspace-1024x184.jpg[/img]
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