diff --git a/image_analysis/IndexAndRefine.cpp b/image_analysis/IndexAndRefine.cpp
index 6311c596..8605b232 100644
--- a/image_analysis/IndexAndRefine.cpp
+++ b/image_analysis/IndexAndRefine.cpp
@@ -258,7 +258,7 @@ std::optional<ScaleMergeResult> IndexAndRefine::ScaleRotationData(const ScaleMer
     ScaleMergeOptions options = opts;
 
     // If the experiment provides a wedge, propagate it
-    if (experiment.GetGoniometer().has_value()) {
+    if (experiment.GetGoniometer().has_value() && rotation_indexer) {
         options.wedge_deg = experiment.GetGoniometer()->GetWedge_deg();
         options.mosaicity_init_deg_vec = mosaicity;
     }
diff --git a/image_analysis/scale_merge/ScaleAndMerge.cpp b/image_analysis/scale_merge/ScaleAndMerge.cpp
index 74f8c667..e8bf2f5e 100644
--- a/image_analysis/scale_merge/ScaleAndMerge.cpp
+++ b/image_analysis/scale_merge/ScaleAndMerge.cpp
@@ -192,7 +192,8 @@ ScaleMergeResult ScaleAndMergeReflectionsCeres(const std::vector<std::vector<Ref
     if (opt.image_cluster <= 0)
         throw std::invalid_argument("image_cluster must be positive");
 
-    const bool refine_partiality = opt.wedge_deg > 0.0;
+    const bool rotation_crystallography = opt.wedge_deg.has_value();
+
     ceres::Problem problem;
 
     struct ObsRef {
@@ -298,7 +299,7 @@ ScaleMergeResult ScaleAndMergeReflectionsCeres(const std::vector<std::vector<Ref
 
     for (const auto &o: obs) {
         auto *cost = new ceres::AutoDiffCostFunction<IntensityResidual, 1, 1, 1, 1>(
-            new IntensityResidual(*o.r, o.sigma, opt.wedge_deg, refine_partiality));
+            new IntensityResidual(*o.r, o.sigma, opt.wedge_deg.value_or(0.0), rotation_crystallography));
         problem.AddResidualBlock(cost,
                                  nullptr,
                                  &g[o.img_id],
@@ -315,25 +316,26 @@ ScaleMergeResult ScaleAndMergeReflectionsCeres(const std::vector<std::vector<Ref
         }
     }
 
+    if (rotation_crystallography) {
+        if (opt.smoothen_g) {
+            for (int i = 0; i < g.size() - 2; ++i) {
+                if (image_slot_used[i] && image_slot_used[i + 1] && image_slot_used[i + 2]) {
+                    auto *cost = new ceres::AutoDiffCostFunction<SmoothnessRegularizationResidual, 1, 1, 1, 1>(
+                        new SmoothnessRegularizationResidual(0.05));
 
-    if (opt.smoothen_g) {
-        for (int i = 0; i < g.size() - 2; ++i) {
-            if (image_slot_used[i] && image_slot_used[i + 1] && image_slot_used[i + 2]) {
-                auto *cost = new ceres::AutoDiffCostFunction<SmoothnessRegularizationResidual, 1, 1, 1, 1>(
-                    new SmoothnessRegularizationResidual(0.05));
-
-                problem.AddResidualBlock(cost, nullptr, &g[i], &g[i + 1], &g[i + 2]);
+                    problem.AddResidualBlock(cost, nullptr, &g[i], &g[i + 1], &g[i + 2]);
+                }
             }
         }
-    }
 
-    if (opt.smoothen_mos && opt.refine_mosaicity) {
-        for (int i = 0; i < mosaicity.size() - 2; ++i) {
-            if (image_slot_used[i] && image_slot_used[i + 1] && image_slot_used[i + 2]) {
-                auto *cost = new ceres::AutoDiffCostFunction<SmoothnessRegularizationResidual, 1, 1, 1, 1>(
-                    new SmoothnessRegularizationResidual(0.05));
+        if (opt.smoothen_mos && opt.refine_mosaicity) {
+            for (int i = 0; i < mosaicity.size() - 2; ++i) {
+                if (image_slot_used[i] && image_slot_used[i + 1] && image_slot_used[i + 2]) {
+                    auto *cost = new ceres::AutoDiffCostFunction<SmoothnessRegularizationResidual, 1, 1, 1, 1>(
+                        new SmoothnessRegularizationResidual(0.05));
 
-                problem.AddResidualBlock(cost, nullptr, &mosaicity[i], &mosaicity[i + 1], &mosaicity[i + 2]);
+                    problem.AddResidualBlock(cost, nullptr, &mosaicity[i], &mosaicity[i + 1], &mosaicity[i + 2]);
+                }
             }
         }
     }
@@ -430,7 +432,7 @@ ScaleMergeResult ScaleAndMergeReflectionsCeres(const std::vector<std::vector<Ref
     corr_obs.reserve(obs.size());
 
     {
-        const double half_wedge = opt.wedge_deg / 2.0;
+        const double half_wedge = opt.wedge_deg.value_or(0.0) / 2.0;
 
         for (const auto &o: obs) {
             const Reflection &r = *o.r;
@@ -439,7 +441,7 @@ ScaleMergeResult ScaleAndMergeReflectionsCeres(const std::vector<std::vector<Ref
 
             // Compute partiality with refined mosaicity
             double partiality;
-            if (refine_partiality && mosaicity[o.img_id] > 0.0) {
+            if (rotation_crystallography && mosaicity[o.img_id] > 0.0) {
                 const double c1 = r.zeta / std::sqrt(2.0);
                 const double arg_plus = (r.delta_phi_deg + half_wedge) * c1 / mosaicity[o.img_id];
                 const double arg_minus = (r.delta_phi_deg - half_wedge) * c1 / mosaicity[o.img_id];
diff --git a/image_analysis/scale_merge/ScaleAndMerge.h b/image_analysis/scale_merge/ScaleAndMerge.h
index 2699f898..764ce01c 100644
--- a/image_analysis/scale_merge/ScaleAndMerge.h
+++ b/image_analysis/scale_merge/ScaleAndMerge.h
@@ -28,7 +28,7 @@ struct ScaleMergeOptions {
     // --- Kabsch(XDS)-style partiality model ---
     // Rotation range (wedge) used in partiality calculation.
     // Set to 0 to disable partiality correction.
-    double wedge_deg = 1.0;
+    std::optional<double> wedge_deg;
 
     // --- Mosaicity (user input in degrees; internally converted to radians) ---
     bool refine_mosaicity = true;