Masks

A mask adjusts part of a photo instead of all of it: darken a bright sky, lift a face, warm one corner. Open a photo in the editor and choose Masks & Cleanup from the icons on the right panel's edge. The page starts with a row of buttons, one for each kind of mask:

• + Linear (M) — a gradient. Drag on the photo from where the effect is full to where it fades out. Good for a sky or a foreground.
• + Radial (Shift+M) — an ellipse. Drag out from its center, or click once for a default size. Hold Shift and scroll over its center to soften or harden the edge.
• + Subject — finds the person or main subject and masks it for you. It only works in the Mac app.
• + Sky — finds the sky and masks it for you.

Subject and Sky have no handles to drag. The mask finds its area in the background and shows a spinner until it is done. While one is picked, the area it covers is tinted red on the photo. If it fails, its label shows a !; hold the pointer over it for the reason, then click Retry.

Adjust a mask

Each mask is listed by kind and number, such as Radial 1. Click one to pick it and drag its handles on the photo. Each mask has its own Temp, Tint, Exposure, Contrast, Highlights, Shadows, Whites, Blacks and Saturation, added on top of the photo's own sliders. Invert swaps where the mask applies and where it doesn't, and Delete removes it. A photo holds up to 16 masks.

Touch Up

The same page holds Touch Up for removing spots. Turn it on (Q) and click a blemish to heal it, up to 64 spots per photo. [ and ] change the brush size.

Masks are stored with the photo's other adjustments in the .lightphotos folder beside it, and they appear in thumbnails and in every export. If a Subject or Sky mask is still being found, export waits for it.