Hello, Graeme! For a long time as I start using the collink in gamut mapping mode, I want ask You a contrast optimizing feature - some kind of a gamut-depended "auto levels". In some cases the source gamut is exceeds the destination gamut only from top or only from bottom of color space (at highlights or at darks exclusively). In some of that cases the contrast may be changed in an effort to the saturation. The contrast (the new source white point) can be optimized in such way that the source gamut exceeding will be more symmetrical. Therefore the source gamut will be a subject of a smaller degree of compression. Not all of output images can get the benefit from contrast optimizing, but some can get much more saturated and pleasant. Another idea of such feature - a smart auto-contrast for underexposed shots. For example take a look at http://www.colour.org/tc8-03/images/ski_pg/Ski_TC8-03_abs.tif test image. While performing of conventional gamut mapping by collink, the output image is much more desaturated as it may be with contrast adjusting.