Digital Light & Color

If I get it anywhere close to right, in 3-tone Transformation the Contrast and Brightness sliders apply 3 separate curves for each tone mask and then blend results (more or less). Now, if for instance my low and high tone ranges are prettey narrow (e.g. 0-20% and 80-100%), the contrast and brightness for the midtones works just fine - changing the curve slope and position above/below the diagonal. But for low and high tones, the sliders seem to almost work the oposite.

My suspicion is that the curve control points for all 3 ranges are in the same place (are they?), even though done separately for each mask, which would kind of explain it: the contrast would change the 1:1 curve into an 'S' or reverse 'S' curve and while increasing the contrast in the midtones, decrease them at the ends. If brightness slider is anchored at the ends, increasing brightness would increase the contrast in the shadows and decrease contrast in highlights, decreasing it would do the opposite. Is that the case and do others have similar problem with it? Cheers!

No, the control points are customized to the tone ranges. Increasing the contrast of the highlights does necessarily decreased their average brightness however since white is fixed; similarly increasing contrast for shadows lightens them on average.