Give ACRIPES a straight BT.709 ramp and end-only tone

src/utils/colorUtils.ts

@@ -172,17 +172,22 @@ export function getSkiaColorMatrix(baseFilter: BaseFilter, adj: ColorAdjustments
       0, 0, 0, 1, 0,
     ];
   } else if (baseFilter === 'monochrome') {
-    // Acros: pure BT.709 grayscale, zero colour leakage. Contrast is a touch
-    // above neutral and eased around mid-grey, so the darks keep texture
-    // instead of plugging to black. (Grain/sharpness stay the user's call —
-    // a film sim here is the colour grade only.)
-    const r = 0.2339;
-    const g = 0.7867;
-    const b = 0.0794;
+    // Acros: pure BT.709 grayscale, zero colour leakage, and NO gain or offset.
+    // The weights sum to 1.0 and the offset is 0, so this matrix is a straight
+    // luminance readout: nothing clips at either end and every grey step the
+    // sensor recorded survives. (An earlier 1.10x / -0.05 version plugged every
+    // black below ~5% and blew every white above ~95% — exactly the fine
+    // graduation this stock is prized for.) The deep black and the highlight
+    // shoulder live in FILM_TONE (toneShader.ts), where the curve can be shaped
+    // one end at a time without touching the midtones. (Grain/sharpness stay
+    // the user's call — a film sim here is the colour grade only.)
+    const r = 0.2126;
+    const g = 0.7152;
+    const b = 0.0722;
     matrix = [
-      r, g, b, 0, -0.05,
-      r, g, b, 0, -0.05,
-      r, g, b, 0, -0.05,
+      r, g, b, 0, 0,
+      r, g, b, 0, 0,
+      r, g, b, 0, 0,
       0, 0, 0, 1, 0,
     ];
   }

src/utils/defaultRecipes.ts

@@ -24,11 +24,12 @@ export const DEFAULT_ADJUSTMENTS: ColorAdjustments = {
 };
 
 // Standard Fuji film simulations. These are the fixed "look" presets shown at
-// the front of the PRESETS chip row: tapping one applies the simulation via
-// its baseFilter colour matrix ONLY — every other knob resets to its neutral
-// default (0 / auto) so the sim is a clean starting point, never a baked
-// recipe. Any look beyond the matrix (grain, DR, CC, contrast…) is added by
-// the user afterwards.
+// the front of the PRESETS chip row: tapping one applies the simulation — its
+// baseFilter colour matrix plus whatever the stock itself carries outside the
+// matrix (its FILM_TONE curve, and a grain amount when the grain IS the look,
+// as on Acros). Every other knob still resets to its neutral default (0 /
+// auto), so a sim is a clean starting point, never a baked recipe; any further
+// look (DR, CC, contrast, more grain) is added by the user afterwards.
 export interface FilmSim {
   id: string; // Recipe-like id used only while the sim is the current selection
   name: string;
@@ -43,7 +44,7 @@ export const FILM_SIMS: FilmSim[] = [
   { id: 'sim-classic-neg', name: 'CLASSIC NEGIPES', baseFilter: 'classic-neg', adjustments: { ...DEFAULT_ADJUSTMENTS } },
   { id: 'sim-astia', name: 'ASTIPES', baseFilter: 'astia', adjustments: { ...DEFAULT_ADJUSTMENTS } },
   { id: 'sim-eterna', name: 'ETERNIPES', baseFilter: 'eterna', adjustments: { ...DEFAULT_ADJUSTMENTS } },
-  { id: 'sim-acros', name: 'ACRIPES', baseFilter: 'monochrome', adjustments: { ...DEFAULT_ADJUSTMENTS } },
+  { id: 'sim-acros', name: 'ACRIPES', baseFilter: 'monochrome', adjustments: { ...DEFAULT_ADJUSTMENTS, grain: 3 } },
   // The rangefinder digital look (M/Q/SL) is not a film stock, so it ships as its own
   // pair instead of one look that has to compromise:
   //   CLASSIC — the stock character: deep solid darks, natural shadows, rich but
@@ -150,15 +151,21 @@ export const DEFAULT_RECIPES: Recipe[] = [
     baseFilter: 'monochrome',
     adjustments: {
       exposure: 0,
-      contrast: 4,
+      // Low: the deep black comes from FILM_TONE's toe and the micro-contrast
+      // from CLARITY, both of which add separation WITHOUT flattening the grey
+      // ramp. The old 4 / highlight 3 / shadow -2 stack was three global
+      // contrast moves on top of a matrix that was already clipping — it
+      // bought its deep black by throwing away every step below 9% and every
+      // one above 91%.
+      contrast: 2,
       saturation: 0,
       temperature: 5000,
       tint: 0,
-      highlight: 3,
-      shadow: -2,
+      highlight: 0,
+      shadow: 0,
       denoise: 0,
       clarity: 3,
-      grain: 6,
+      grain: 5,
       colorChrome: 'none',
       colorChromeBlue: 'none',
       dynamicRange: 'auto',

src/utils/toneShader.ts

@@ -189,6 +189,16 @@ export interface ToneUniforms {
 const FILM_TONE: Partial<Record<BaseFilter, Partial<ToneUniforms>>> = {
   'classic-chrome': { sh: -0.28 },
   'classic-neg': { shT: [-0.018, 0.009, 0.013], hlT: [0.024, 0.008, -0.012] },
+  // Acros. A black-and-white stock IS its grey ramp, so this entry only shapes
+  // the two ENDS and leaves the middle an identity: a smooth shadow toe that
+  // reaches a true black (no film-base lift, no flat grey wash) and a highlight
+  // shoulder that stops just short of white instead of clipping a cloud to
+  // paper. Mid-tones see neither mask, so the ramp keeps every step the matrix
+  // handed over — which is what 'deep black' costs in a colour stock and does
+  // not have to cost here.
+  // Gains are TONE_SKSL's own (sh * 0.34, hl * 0.22), so -0.12 puts the toe at
+  // ~5% and -0.05 trims the top ~1%.
+  monochrome: { sh: -0.12, hl: -0.05 },
 };
 
 export function getToneUniforms(adj: ColorAdjustments, baseFilter?: BaseFilter): ToneUniforms {