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+# ✅ At least two thirds of the title's disagreement is GEOMETRY, not tone
+
+**Classification: measured**, on committed captures. Answers a question the
+pending rotation decision needs: *how much would drawing the rotation actually
+buy?*
+
+Two separate effects are known to make our renders differ from the console:
+
+* the **tone curve** — the console renders midtones brighter than we do
+  ([`ui-render-tone-curve.md`](ui-render-tone-curve.md)), and its single-exponent
+  model is refuted above render ≈ 40;
+* the **missing rotation** — our blit draws axis-aligned rectangles, so the
+  title's two tilted light sweeps land as upright bars
+  ([`ui-keyframe-rotation.md`](ui-keyframe-rotation.md)).
+
+They are confounded in any whole-frame number. This separates them.
+
+## Method, and why the split is an upper bound on tone
+
+A **per-level lookup table** fitted on a screen is the most general tone model
+there is: it maps every render level to whatever capture level minimises the
+error, with no functional form assumed. **Whatever such a LUT cannot close is,
+by construction, not a per-pixel-level effect** — it is spatial.
+
+So fitting a LUT *on the screen itself* and measuring what remains gives an
+**upper bound on the tone share** and a **lower bound on the geometry share**.
+
+## The positive control
+
+The method must be able to close a residual that really is tone. On the **main
+menu** — where the port measures only 0.06 % of pixels differing, so geometry is
+essentially right — it does:
+
+| | mean abs difference | closed |
+|---|---|---|
+| main menu, uncorrected | 9.26 | — |
+| **main menu + LUT fitted on the main menu** | **2.75** | **70.3 %** |
+
+✅ The instrument works: a tone-dominated residual collapses by 70 %.
+
+## The result
+
+| | mean abs difference | closed |
+|---|---|---|
+| title, uncorrected | 10.92 | — |
+| **title + LUT fitted on the title** | **7.42** | **32.0 %** |
+
+🔴 **At most 32 % of the title's disagreement is a tone effect, so at least 68 %
+is spatial** — content in the wrong place. That is where the rotation lives, and
+it makes the rotation the dominant term by roughly two to one.
+
+⚠️ The same-screen LUT is *fitted*, so 32 % is generous to tone. The true tone
+share is smaller and the geometry share larger.
+
+## 🔴 And a claim this refutes: there is no single transferable tone curve
+
+Fitting on one screen and applying to the other:
+
+| | closed |
+|---|---|
+| main menu + LUT fitted on the **title** | **+29.7 %** |
+| title + LUT fitted on the **main menu** | **−24.0 %** ✗ |
+
+**The menu's curve makes the title worse.** A curve fitted on a dark, flat screen
+is unconstrained at the bright end — the menu's populated range is levels 5–204
+with few bright pixels — and extrapolating it onto the title's planet and
+wordmark actively harms.
+
+⚠️ So *"the tone curve"* is not one thing that can be measured once and applied.
+This extends [`ui-render-tone-curve.md`](ui-render-tone-curve.md)'s refutation of
+the single **exponent**: even a full per-level LUT fails to transfer between
+screens. **A consumer must not carry a global tone correction.**
+
+## Reach
+
+* Two screens, one capture each; the title capture is the plate-free frame and
+  our render is at rest, so they are **the same screen but not the same
+  instant** — a looser pairing than the port's posed comparison, which is why
+  the absolute numbers here (10.92) are larger than its 1.81 % of pixels.
+  ⚠️ The *ratio* is what this page claims, not the absolute level.
+* Our render draws the sweeps' **parent** record only — the pre-leaf-fix state —
+  so the geometry share measured here includes both the missing rotation and the
+  missing leaf placement. Both are closed by the same decision.