| Soft clip parameters demystified | 5.3 Provided profiles |
5.3.
Gamut compression can be achieved in general by reducing the chroma of colors, thus moving colors slightly towards the gray axis.
In the case of recording CRT monitor images to film, due to the fact that film gamut reaches its maximum chroma at lower levels of lightness than the monitor gamut, carefully reducing lightness also moves colors into the film gamut.
Best results are achieved by balancing chroma and lightness reduction. The soft clip parameters specify the amount of change in terms of the perceptual difference between the two gamut’s, e.g. setting dC.R to 50% reduces red chroma by 50% of the difference between the pure red of the monitor and film gamut, respectively.
Both chroma and lightness change depending on hue, chroma and lightness, so that dark and unsaturated colors are affected less than bright, highly saturated colors.
For colors at which the film chroma is greater than the monitor chroma, the chroma difference should be 0 or negative to gain gamut compression, otherwise gamut extension would be the effect. This is especially true for yellow.
Provided with the color management are the following ICC profiles:
profile name: sony_hd.icm description:
Sony BVM
device dependent RGB values:
16 bit RGB values,
representing the SMPTE260M video safe YUV range. That means:
RGB=0 matches YUV=64,512,512 and RGB=65535 matches YUV=940,512,512 for 10bit YUV.
profile name: vision.icm description:
Kodak Vision print stock projected by a xenon lamp
Color Management
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