diff --git a/libs/renderengine/gl/GLESRenderEngine.cpp b/libs/renderengine/gl/GLESRenderEngine.cpp
index d87315f..b5510d9 100644
--- a/libs/renderengine/gl/GLESRenderEngine.cpp
+++ b/libs/renderengine/gl/GLESRenderEngine.cpp
@@ -1233,8 +1233,10 @@
             }
         }
 
-        mState.maxMasteringLuminance = layer->source.buffer.maxMasteringLuminance;
-        mState.maxContentLuminance = layer->source.buffer.maxContentLuminance;
+        // Ensure luminance is at least 100 nits to avoid div-by-zero
+        const float maxLuminance = std::max(100.f, layer->source.buffer.maxLuminanceNits);
+        mState.maxMasteringLuminance = maxLuminance;
+        mState.maxContentLuminance = maxLuminance;
         mState.projectionMatrix = projectionMatrix * layer->geometry.positionTransform;
 
         const FloatRect bounds = layer->geometry.boundaries;
diff --git a/libs/renderengine/include/renderengine/DisplaySettings.h b/libs/renderengine/include/renderengine/DisplaySettings.h
index a637796..53fa622 100644
--- a/libs/renderengine/include/renderengine/DisplaySettings.h
+++ b/libs/renderengine/include/renderengine/DisplaySettings.h
@@ -60,6 +60,9 @@
     // capture of a device in landscape while the buffer is in portrait
     // orientation.
     uint32_t orientation = ui::Transform::ROT_0;
+
+    // SDR white point, -1f if unknown
+    float sdrWhitePointNits = -1.f;
 };
 
 static inline bool operator==(const DisplaySettings& lhs, const DisplaySettings& rhs) {
diff --git a/libs/renderengine/include/renderengine/LayerSettings.h b/libs/renderengine/include/renderengine/LayerSettings.h
index e976a5a..993448d 100644
--- a/libs/renderengine/include/renderengine/LayerSettings.h
+++ b/libs/renderengine/include/renderengine/LayerSettings.h
@@ -64,8 +64,8 @@
 
     // HDR color-space setting for Y410.
     bool isY410BT2020 = false;
-    float maxMasteringLuminance = 0.0;
-    float maxContentLuminance = 0.0;
+
+    float maxLuminanceNits = 0.0;
 };
 
 // Metadata describing the layer geometry.
@@ -175,8 +175,7 @@
             lhs.textureTransform == rhs.textureTransform &&
             lhs.usePremultipliedAlpha == rhs.usePremultipliedAlpha &&
             lhs.isOpaque == rhs.isOpaque && lhs.isY410BT2020 == rhs.isY410BT2020 &&
-            lhs.maxMasteringLuminance == rhs.maxMasteringLuminance &&
-            lhs.maxContentLuminance == rhs.maxContentLuminance;
+            lhs.maxLuminanceNits == rhs.maxLuminanceNits;
 }
 
 static inline bool operator==(const Geometry& lhs, const Geometry& rhs) {
@@ -237,8 +236,7 @@
     *os << "\n    .usePremultipliedAlpha = " << settings.usePremultipliedAlpha;
     *os << "\n    .isOpaque = " << settings.isOpaque;
     *os << "\n    .isY410BT2020 = " << settings.isY410BT2020;
-    *os << "\n    .maxMasteringLuminance = " << settings.maxMasteringLuminance;
-    *os << "\n    .maxContentLuminance = " << settings.maxContentLuminance;
+    *os << "\n    .maxLuminanceNits = " << settings.maxLuminanceNits;
     *os << "\n}";
 }
 
diff --git a/libs/renderengine/skia/Cache.cpp b/libs/renderengine/skia/Cache.cpp
index 6ab93df..58d124a 100644
--- a/libs/renderengine/skia/Cache.cpp
+++ b/libs/renderengine/skia/Cache.cpp
@@ -108,8 +108,7 @@
             .source = PixelSource{.buffer =
                                           Buffer{
                                                   .buffer = srcTexture,
-                                                  .maxMasteringLuminance = 1000.f,
-                                                  .maxContentLuminance = 1000.f,
+                                                  .maxLuminanceNits = 1000.f,
                                           }},
     };
 
@@ -205,8 +204,7 @@
             .source = PixelSource{.buffer =
                                           Buffer{
                                                   .buffer = srcTexture,
-                                                  .maxMasteringLuminance = 1000.f,
-                                                  .maxContentLuminance = 1000.f,
+                                                  .maxLuminanceNits = 1000.f,
                                                   .textureTransform = kScaleYOnly,
                                           }},
             .sourceDataspace = kOtherDataSpace,
diff --git a/libs/renderengine/skia/SkiaGLRenderEngine.cpp b/libs/renderengine/skia/SkiaGLRenderEngine.cpp
index acdb78a..160ffb3 100644
--- a/libs/renderengine/skia/SkiaGLRenderEngine.cpp
+++ b/libs/renderengine/skia/SkiaGLRenderEngine.cpp
@@ -567,10 +567,14 @@
         } else {
             runtimeEffect = effectIter->second;
         }
+        float maxLuminance = layer->source.buffer.maxLuminanceNits;
+        // If the buffer doesn't have a max luminance, treat it as SDR & use the display's SDR
+        // white point
+        if (maxLuminance <= 0.f) {
+            maxLuminance = display.sdrWhitePointNits;
+        }
         return createLinearEffectShader(shader, effect, runtimeEffect, layer->colorTransform,
-                                        display.maxLuminance,
-                                        layer->source.buffer.maxMasteringLuminance,
-                                        layer->source.buffer.maxContentLuminance);
+                                        display.maxLuminance, maxLuminance);
     }
     return shader;
 }
@@ -866,7 +870,9 @@
 
         const bool requiresLinearEffect = layer->colorTransform != mat4() ||
                 (mUseColorManagement &&
-                 needsToneMapping(layer->sourceDataspace, display.outputDataspace));
+                 needsToneMapping(layer->sourceDataspace, display.outputDataspace)) ||
+                (display.sdrWhitePointNits > 0.f &&
+                 display.sdrWhitePointNits != display.maxLuminance);
 
         // quick abort from drawing the remaining portion of the layer
         if (layer->alpha == 0 && !requiresLinearEffect && !layer->disableBlending &&
diff --git a/libs/renderengine/skia/filters/LinearEffect.cpp b/libs/renderengine/skia/filters/LinearEffect.cpp
index 0fbd669..9b044e1 100644
--- a/libs/renderengine/skia/filters/LinearEffect.cpp
+++ b/libs/renderengine/skia/filters/LinearEffect.cpp
@@ -127,7 +127,7 @@
         default:
             shader.append(R"(
                     float3 ScaleLuminance(float3 xyz) {
-                        return xyz * in_displayMaxLuminance;
+                        return xyz * in_inputMaxLuminance;
                     }
                 )");
             break;
@@ -448,7 +448,7 @@
 sk_sp<SkShader> createLinearEffectShader(sk_sp<SkShader> shader, const LinearEffect& linearEffect,
                                          sk_sp<SkRuntimeEffect> runtimeEffect,
                                          const mat4& colorTransform, float maxDisplayLuminance,
-                                         float maxMasteringLuminance, float maxContentLuminance) {
+                                         float maxLuminance) {
     ATRACE_CALL();
     SkRuntimeShaderBuilder effectBuilder(runtimeEffect);
 
@@ -467,8 +467,10 @@
     }
 
     effectBuilder.uniform("in_displayMaxLuminance") = maxDisplayLuminance;
+    // If the input luminance is unknown, use display luminance (aka, no-op any luminance changes)
+    // This will be the case for eg screenshots in addition to uncalibrated displays
     effectBuilder.uniform("in_inputMaxLuminance") =
-            std::min(maxMasteringLuminance, maxContentLuminance);
+            maxLuminance > 0 ? maxLuminance : maxDisplayLuminance;
     return effectBuilder.makeShader(nullptr, false);
 }
 
diff --git a/libs/renderengine/skia/filters/LinearEffect.h b/libs/renderengine/skia/filters/LinearEffect.h
index 20b8338..9e989ea 100644
--- a/libs/renderengine/skia/filters/LinearEffect.h
+++ b/libs/renderengine/skia/filters/LinearEffect.h
@@ -98,7 +98,7 @@
                                          const LinearEffect& linearEffect,
                                          sk_sp<SkRuntimeEffect> runtimeEffect,
                                          const mat4& colorTransform, float maxDisplayLuminance,
-                                         float maxMasteringLuminance, float maxContentLuminance);
+                                         float maxLuminance);
 } // namespace skia
 } // namespace renderengine
 } // namespace android