Make an image black and white

The saturation slider is at zero, which removes the colour and leaves the brightness of each pixel. It is a slider rather than a button because half way is useful too — a muted, partly desaturated image is a common look and there is no reason to make you choose between full colour and none.

Black and white images often want more contrast than the colour original did, since colour was doing some of the work of separating the subject from the background. The contrast slider is next to it.

The conversion happens on the way out, so the original keeps its colour and the slider can go back at any point. Applying it across a batch is one press once the images are selected, which is usually the reason to be here at all: a set of headshots or product shots that have to match each other.