I'm getting very different gray tones from two different ways of reducing saturation:
- Left – uses a layer with blend mode set to Saturation. The layer's color has 0 saturation (e.g. white or black fill), and layer is 100% opacity.
- Right – uses an Adjustment Layer (or Image > Adjustments > Hue/Saturation gives same result).
Why are they different? Shouldn't both be the same as setting the Saturation to 0 in HSB color space on all the pixels?
Here's the original image for comparison: