Four numbers and an Auto button
The Light step has four controls, each from −100 to 100: brightness (a midtone curve), contrast (an S-curve above zero, a flattening below), highlights (negative pulls bright areas back) and shadows (positive opens dark areas). Auto reads the frame and sets them, together with warmth and saturation, as numbers.
Brightening cannot recover what the camera never recorded: a sky that is pure white stays white, and a black shadow opened far enough shows noise. Drag the seam at 1:1 (press Z) to see that before you save.
Related: Auto fix a photo runs Auto as soon as the photo opens; Lighten one area of a photo for one shaded patch.
Questions about brightening
- Brightness or shadows — which do I want?
- Brightness moves the midtones and leaves the ends of the range nearly where they were. Shadows opens only the dark areas. A photo that is dark all over wants brightness; a photo with a bright sky and a dark foreground wants shadows up and highlights down.
- Why did Auto pick those numbers?
- It reads the median and spread of the brightness, how much is clipped at each end, and the average colour cast, and writes six values from those. They are shown in the sliders, so you can see exactly what it did and move any of them. Undo takes the lot back.
- Only one corner is dark.
- Then a whole-frame control will brighten the parts that were already right. Lighten one area of a photo places a soft lift on just the shaded part.
