Brightness & contrast

Brightness makes the whole picture lighter or darker. Raising it lifts the shadows as well as the mid-tones, which helps a dark indoor photo, while lowering it scales every colour towards black. Contrast works differently: it pushes dark areas darker and light areas lighter around the middle grey, so the picture gains punch without getting brighter overall. Turning contrast down does the opposite and flattens the image towards grey.

Saturation controls how strong the colours are. Small increases help a dull, overcast shot, but large ones quickly make skin look orange and skies look fake. At the far left, −100, the photo becomes black and white. Warmth adds red and takes away blue, or the reverse when you move it left, which is how you correct the blue cast of shade or the yellow of indoor bulbs.

There's no separate exposure slider, and Brightness is the closest thing to one, with an important limit. It can only work with the detail the file already holds. A sky that came out pure white or a shadow that came out pure black has no detail left to bring back, and pushing Brightness too far turns bright areas into flat white patches of their own.

Every slider runs from −100 to +100 and starts at a gentle +15 brightness and +10 contrast. Small moves usually look best: raise Brightness first, add a little Contrast so the result doesn't look washed out, then fine-tune colour. Show original lets you compare as you go. The same settings are applied to every photo in the list, so a set taken in the same light gets a matching fix in one go.