Curves (RGB)
Curves is the closest thing Darkroom has to a blank canvas. With it you can fix exposure, build contrast exactly where you want it, lift blacks into a soft fade, and tune color tone region by region. It's powerful enough that you can recreate most popular film and filter looks with this one tool — which is exactly why it became the foundation Darkroom was built around.
A simple mental model helps: every pixel is three buckets of light — red, green, and blue. Curves sorts your photo into tonal regions (blacks, shadows, midtones, highlights, whites) and lets you add or drain light from those buckets within each region. Pick a channel from the selector on the left — RGB moves all three buckets at once (brightness and contrast); Red, Green, and Blue move one at a time (color and tone). You'll find Curves in the Edit view toolbar.

The RGB curve: selective brightness and contrast
The RGB curve controls the amount of light in your photo — but unlike the Brightness slider, it lets you do it selectively, one tonal region at a time. That's the whole point. Brighten a dark landscape foreground by pulling up only the shadows and midtones, and your clouds keep all their detail instead of blowing out.
Two shapes do most of the work:
- A bow (up or down) raises or lowers brightness across the regions you bend. Bow the shadows up to open them; bow the highlights down to rein them in.
- An S-curve adds contrast: lift the highlights, drop the shadows, and the image gains punch while the midtones hold. Flatten it instead to soften a harsh photo.
Pull a region all the way up and it goes white; all the way down and it goes black — handy for crushing shadows into a silhouette or washing out highlights to focus attention. Keep an eye on the Histogram so you don't clip more than you mean to.
Per-channel curves: color and film tone
The Red, Green, and Blue channels are where personal style lives. Adjusting them in different regions gives a photo a two-tone cast — say, slightly more red in the shadows and a touch less in the highlights — which is precisely how film stocks earned their signature looks. A film that was more sensitive to green in low light gave shadows a green cast; pull the green channel up in the shadows and you've recreated it.
The trick is restraint and coordination. Color curves usually move together: to build a contrasty, toned look, give all three an S-curve and let the small differences between them create the tone. Big moves on a single channel contaminate neutrals and skin, so make small adjustments — tapping just above or below the curve nudges it 1% at a time for fine control.
Fades
A fade is just a curve move: lift the blacks toward gray and drop the whites toward gray. The result is the soft, airy look that defined the Instagram and VSCO era — and because it crushes nearby values together, it also simplifies detail and pulls the eye toward your focal point. Push it gently for a whisper of softness, or hard for a bold, washed-out style. Bias the channels differently and your fade picks up color: warmer highlights, cooler shadows.
A useful habit
When an edit starts looking strange and you can't tell which channel is causing it, long-press the channel selector to toggle that single curve off while keeping everything else in place. It's the fastest way to isolate what a curve is actually doing.
Curves works best early, before finishing effects, and pairs naturally with Color Grading for stylistic color — then save the whole thing as a preset to reuse it.
Related
- Histogram to watch clipping while you work
- Color (HSL) for targeted, per-color fixes
- Using Curves, Part 1 — brightness and contrast in depth
- Using Curves, Part 2 — color, tone, and film emulation