Correct what D20 claimed the profile tables would do for colour

Measured after building them, on four of the library's 6D DNGs: Adobe
Standard's tables lower mean saturation by 3-9 % at defaults, and the
look at 200 % lowers it further. The 6D's look table scales saturation
by 0.925 in its darkest value rows; it was tuned to sit under Camera
Raw's default RGB tone curve, which DarkRoom does not apply, and the
dark-tone desaturation is what is left without it. On _MG_9080 the
Lightroom preview measures 0.49, the matrix alone 0.38, the profile
0.35.

So the spec's "that gap is most of why the same file looks flatter"
was wrong: the gap is tone. The tables stay — they put each hue where
Adobe put it — and the spec, D20 and the Vivid file now say so.
"Stronger camera look" is removed: a stronger Adobe Standard look is a
less saturated picture, the opposite of its name. The Vivid presets,
measured at 0.40-0.46 on the same frame, are what answers "more
colourful" today.

docs/dev/camera-profiles.md

@@ -14,13 +14,25 @@ DarkRoom already applies, plus two lookup tables indexed by hue, saturation and
 - **`ProfileHueSatMap`** — a calibration. It corrects what a 3×3 cannot: a sensor whose reds and
   oranges sit in the wrong place relative to its blues, which no linear map fixes. Two copies, one
   per calibration illuminant, interpolated like the matrices.
-- **`ProfileLookTable`** — a rendering intent. The "Adobe Standard" look: richer blues and greens,
-  warmer yellows, skin held where it is. The difference between Adobe Standard, Adobe Color and
-  Adobe Vivid is mostly this table.
+- **`ProfileLookTable`** — a rendering intent: hue shifts of up to ±18° by hue, and saturation
+  and value scales that vary with brightness. The difference between Adobe Standard, Adobe Color
+  and Adobe Vivid is largely this table, together with each profile's tone curve.
 
-Without them a raw renders through the matrix alone, which is accurate on a ColorChecker and reads
-as flat next to Lightroom. The first complaint FR-DEV-3e's rationale names is exactly this, and
-the per-body base curves D19 retired were the cheaper stand-in for it.
+Without them a raw renders through the matrix alone, which is accurate on a ColorChecker and is
+not what Lightroom showed for the same file.
+
+**What the tables do *not* do is make a photograph more saturated.** Measured after the build
+(2026-10-02), on four of the library's 6D DNGs rendered at defaults: Adobe Standard's tables
+*lower* mean saturation by 3–9 %, and the look at 200 % lowers it further. The 6D's look table
+scales saturation by 0.925 in its darkest value rows and by 1.0 from about a fifth of full scale
+up, and its HueSatMap adds about 1 %. Adobe Standard was tuned to sit under Camera Raw's default
+RGB tone curve, which raises saturation in the shadows and midtones, and the look's dark-tone
+desaturation offsets it. Without that curve (§6) the offset is all that is left. On `_MG_9080`, Lightroom 6's own preview
+measures 0.49 mean HSV saturation; the matrix alone renders 0.38, Adobe Standard's tables 0.35.
+That preview also carries whatever was edited in Lightroom, so it is not a clean reference — but
+the direction is unambiguous: **the gap to Lightroom's colour is mostly tone, not the profile's
+tables.** The tables still matter for hue: they are what puts each body's reds, skin and foliage
+where Adobe put them.
 
 **What the library holds** (catalog of 2026-10-02): 17,286 of its raws are Canon EOS 6D. The
 9,348 DNGs were written by Lightroom 6.14 and every one sampled embeds *Adobe Standard* with both
@@ -212,7 +224,8 @@ action sits on that line.
 
 ## 9. Vivid presets
 
-Independent of the tables, and shipped in the same change: a *Vivid* section of read-only presets
+Independent of the tables, and — given §1's measurement — the part of this change that actually
+answers "more colourful". Shipped in the same change: a *Vivid* section of read-only presets
 (`presets/vivid.drpl`) for the "more colourful than the default" request. They use only operations
 every photograph has — vibrance, saturation, the colour mixer, colour grading, contrast — so they
 work on JPEGs and on bodies with no profile, and change only what they name (FR-DEV-6):
@@ -223,6 +236,11 @@ work on JPEGs and on bodies with no profile, and change only what they name (FR-
 - **Vivid warm** — oranges and yellows up, a warm highlight cast: golden hour.
 - **Vivid portrait** — vibrance (which protects skin) with the orange and red bands held back.
 
+Measured on `_MG_9080` (mean HSV saturation; Lightroom's preview 0.49, DarkRoom's default 0.35):
+Vivid 0.40, Vivid strong 0.44, Vivid landscape 0.46, Vivid warm 0.38, Vivid portrait 0.37 — the
+last two move particular bands, not the whole frame. Rendered with `cargo run --release -p dr-gpu
+--example develop -- FILE.dng out.ppm "preset:Vivid"`.
+
 They are bounded by the existing `bundled.rs` tests: every key names a real parameter, every value
 is inside its control's range, and every preset changes something.