diff --git a/core/dr-pipeline/ops/vibrance.yaml b/core/dr-pipeline/ops/vibrance.yaml
index dd51f23..c034b14 100644
--- a/core/dr-pipeline/ops/vibrance.yaml
+++ b/core/dr-pipeline/ops/vibrance.yaml
@@ -21,24 +21,41 @@ params:
     kind: amount
 
 uniforms:
-  amount: vibrance / 100
+  amount:
+    value: vibrance / 100 * 1.3
+    doc: |
+      Scaled so that a value here does what the same value of Lightroom's
+      Vibrance does. Measured, not chosen: fitted on 45 Lightroom exports whose
+      only colour setting was Vibrance (about +24), against their raws.
 
-helpers: [luminance, tone_position, colour_saturation]
+helpers: [luminance]
 
 wgsl: |
   let luma = luminance(c);
-  let sat = colour_saturation(c);
+
+  // How saturated a colour *looks*, so measured on display-encoded values.
+  // In scene-linear light an ordinary tan reads as 0.78 saturated and the
+  // falloff below would leave it a twentieth of the effect; encoded, it reads
+  // as 0.5, which is what the eye sees.
+  let e = pow(max(c, vec3<f32>(0.0)), vec3<f32>(1.0 / 2.2));
+  let e_hi = max(e.r, max(e.g, e.b));
+  let e_lo = min(e.r, min(e.g, e.b));
+  let sat = select(0.0, (e_hi - e_lo) / e_hi, e_hi > 0.00001);
 
   // The vibrance curve: full effect on grey, tapering to nothing on colours
   // that are already saturated. Squaring the falloff keeps the mid-range
   // responsive while still protecting the extremes.
   let falloff = (1.0 - sat) * (1.0 - sat);
 
-  // Skin protection. Skin sits in a narrow band of hue where red leads green
-  // leads blue; pushing it is what makes vibrance look wrong on portraits.
-  // Detected by channel ordering rather than a hue angle, which costs a
-  // conversion and buys nothing here.
-  let is_skin = f32(c.r > c.g && c.g > c.b);
+  // Skin protection, for skin: hues between about 10 and 50 degrees (red
+  // leading, green between red and blue) that are not strongly saturated.
+  // Red-over-green-over-blue alone is every warm colour in a photograph —
+  // wood, sand, brick, sunlit grass — and halving all of them is most of why
+  // vibrance used to do so little.
+  let span = max(e_hi - e_lo, 0.00001);
+  let skin_hue = select(0.0, 60.0 * (e.g - e.b) / span, e.r >= e.g && e.g >= e.b);
+  let in_band = smoothstep(4.0, 12.0, skin_hue) * (1.0 - smoothstep(42.0, 52.0, skin_hue));
+  let is_skin = in_band * (1.0 - smoothstep(0.45, 0.7, sat)) * f32(e.r >= e.g && e.g >= e.b);
   let skin_guard = 1.0 - is_skin * 0.5;
 
   let strength = amount * falloff * skin_guard;
@@ -49,9 +66,18 @@ tests:
   - name: it_starts_neutral
     expect_active: false
 
-  - name: the_amount_is_normalised_to_unit_range
+  - name: the_amount_is_lightrooms_scale
+    why: |
+      Fitted against Lightroom exports: DarkRoom's vibrance at a value does
+      what Lightroom's does at the same value.
     set: { vibrance: 100 }
-    expect: { amount: 1.0 }
+    expect: { amount: 1.3 }
+
+  - name: saturation_is_judged_as_displayed
+    why: |
+      Judged in scene-linear light, ordinary warm colours read as nearly
+      saturated and get almost none of the effect.
+    expect_wgsl: ["let e = pow(max(c, vec3<f32>(0.0)), vec3<f32>(1.0 / 2.2));"]
 
   - name: muted_colours_get_more_than_saturated_ones
     why: |