Brightness, Exposure and Hue/Saturation compared

Three adjustments do a lot of the everyday work in photo editing. Brightness/Contrast, Exposure and Hue/Saturation are simple to understand, and knowing which to reach for saves time. Here's how each one behaves in Paint by Zaweba and where it fits.

Brightness/Contrast

Brightness makes the picture lighter or darker. Contrast spreads the tones apart or squeezes them together. It's the most straightforward way to fix a photo that's a bit dull.

There's also a legacy option, which switches the adjustment to an older way of working that some people know from other editors. If you're matching an edit made that way, or a result looks different from what you expected, try it both ways and compare. Watch the brightest and darkest parts of the picture as you do, since that's where any loss of detail shows first.

Exposure

Exposure works in stops, the same unit a camera uses. One stop brighter doubles the light; one stop darker halves it. That makes it the natural choice for photos that were simply under or over exposed in camera.

It has three controls: exposure, offset and gamma. Exposure changes the brightness in stops. Offset shifts the darkest tones, so a negative offset deepens shadows and a positive one lifts them. Gamma adjusts the midtones.

Exposure works in linear light, the way light actually adds up. That's why it behaves differently from Brightness: a stop brighter affects highlights more than shadows, as real light does. It suits high bit depth photos and HDR work especially well.

Hue/Saturation

Hue shifts colours around the colour wheel. Saturation makes them stronger or weaker.

There's a master setting that affects every colour, and separate ranges for reds, yellows, greens, cyans, blues and magentas. Each range has draggable limits, so you can widen or narrow exactly which shades are affected. That's how you change the colour of one thing in a photo, such as turning a red car blue, without changing everything else that's slightly red.

On-image drag lets you press on a colour in the picture and drag to change it, so you don't have to work out which range it belongs to.

Colourise turns the picture into a single tint. Use it for a quick sepia, a blue night look or a coloured monochrome.

Which to use

Use Exposure for a photo that was taken too dark or too bright. It's the closest to setting the camera right in the first place.

Use Brightness/Contrast for a quick general boost when a photo looks flat.

Use Hue/Saturation for colour: strengthening or calming colour overall, or changing one colour.

For finer tonal control, Levels and Curves go further, but these three cover a great many photos.

Overdone edits

Pushing saturation too far is the classic. Colours go garish and skin turns orange. Moderate amounts, or Vibrance in the simple colour adjustments, look more natural.

Using Brightness when Exposure would be better leads to washed-out highlights on underexposed photos. Try Exposure first for exposure problems.

With Hue/Saturation, check the range limits after on-image drag. If other objects change colour too, narrow the limits.

As adjustment layers, all three can be reopened and masked. Used that way in Paint by Zaweba, they are a safe first step before anything more involved.