diff --git a/image_analysis/scale_merge/RotationScaleMerge.cpp b/image_analysis/scale_merge/RotationScaleMerge.cpp
index b37f3237..c8e3f4ae 100644
--- a/image_analysis/scale_merge/RotationScaleMerge.cpp
+++ b/image_analysis/scale_merge/RotationScaleMerge.cpp
@@ -29,7 +29,8 @@
 namespace {
     // These mirror the per-image ScaleOnTheFly / Merge rocking-curve physics verbatim so this flat
     // implementation is numerically identical - see the comments there for the details.
-    constexpr size_t MIN_REFLECTIONS = 20;   // per-frame scale needs at least this many
+    constexpr size_t MIN_REFLECTIONS = 20;
+    constexpr int64_t MIN_REFLECTIONS_FOR_IMAGE_CC = 20;   // below this a frame's CC means nothing   // per-frame scale needs at least this many
     constexpr double SCALE_ROBUST_K = 3.0;   // Cauchy loss scale (sigma units) for the per-frame G fit
 
     // A fitted per-frame scale below this fraction of the run's median is not a measurement of anything:
@@ -175,6 +176,7 @@ RotationScaleMerge::RotationScaleMerge(const DiffractionExperiment &experiment,
     merge_friedel = s.GetMergeFriedel();
     capture_uncertainty_coeff = s.GetCaptureUncertaintyCoeff();
     min_captured_fraction = s.GetMinCapturedFraction();
+    min_cc_for_image = s.GetMinCCForImage();
     reject_nsigma = s.GetOutlierRejectNsigma();
     reject_outliers = reject_nsigma > 0.0;
     rfree_fraction = s.GetRfreeFraction();
@@ -1993,6 +1995,35 @@ RotationScaleMerge::Result RotationScaleMerge::Run(bool for_search,
     }
     FinalizePerFrameScale(cc, cc_n, partial_scaled);
 
+    // --- 2b. Drop frames that do not agree with the merged reference (--min-image-cc). ---
+    if (min_cc_for_image > 0.0) {
+        std::vector<uint8_t> reject(n_frames, 0);
+        int n_rejected = 0;
+        for (int f = 0; f < n_frames; ++f)
+            if (std::isfinite(cc[f]) && cc_n[f] >= MIN_REFLECTIONS_FOR_IMAGE_CC && cc[f] < min_cc_for_image) {
+                reject[f] = 1;
+                ++n_rejected;
+            }
+        if (n_rejected > 0) {
+            // Zeroing corr is how a frame leaves the pipeline: every consumer requires corr > 0, so the
+            // frame's partials stop being usable for the combine, the merge and the error model alike.
+            bool rejected_on_gpu = false;
+#ifdef JFJOCH_USE_CUDA
+            if (gpu_active_) {
+                std::vector<double> ratio(n_frames, 1.0);
+                for (int f = 0; f < n_frames; ++f) if (reject[f]) ratio[f] = 0.0;
+                gpu_->SmoothCorr(reject.data(), ratio.data());
+                rejected_on_gpu = true;
+            }
+#endif
+            if (!rejected_on_gpu)
+                for (auto &o : partials)
+                    if (reject[o.frame]) o.corr = 0.0f;
+            logger.Info("Rejected {} of {} frames correlating below {:.2f} with the merged reference",
+                        n_rejected, n_frames, min_cc_for_image);
+        }
+    }
+
     // --- 3. 3D combine of per-frame partials into fulls (fulls inherit their ASU group here). ---
     bool combined_on_gpu = false;
     bool scaled_fulls_on_gpu = false;
diff --git a/image_analysis/scale_merge/RotationScaleMerge.h b/image_analysis/scale_merge/RotationScaleMerge.h
index 2dd3be38..adb37fa9 100644
--- a/image_analysis/scale_merge/RotationScaleMerge.h
+++ b/image_analysis/scale_merge/RotationScaleMerge.h
@@ -100,6 +100,12 @@ private:
     bool merge_friedel = true;
     double capture_uncertainty_coeff = 0.0;
     double min_captured_fraction = 0.0;
+
+    // Drop a frame's observations entirely when the frame disagrees with the merged reference below this
+    // correlation (--min-image-cc). A mis-centred or off-crystal frame still produces spots, still
+    // indexes and still integrates - it just measures something that is not the crystal's diffraction,
+    // and nothing downstream removes it. 0 = off.
+    double min_cc_for_image = 0.0;
     double reject_nsigma = 0.0;
     bool reject_outliers = false;
     double rfree_fraction = 0.0;
diff --git a/rugnux/rugnux_cli.cpp b/rugnux/rugnux_cli.cpp
index 383625d9..d1e1e66f 100644
--- a/rugnux/rugnux_cli.cpp
+++ b/rugnux/rugnux_cli.cpp
@@ -1425,10 +1425,6 @@ int main(int argc, char **argv) {
     scaling_settings.CaptureUncertaintyCoeff(capture_uncertainty_arg.value_or(rotation_indexing ? 1.0 : 0.0));
     scaling_settings.ForcedMosaicity(forced_mosaicity_arg);
     scaling_settings.MinCCForImage(min_image_cc / 100.0);   // --min-image-cc is in percent; the setting is a fraction
-    // The per-image CC filter is consumed by the stills merge (MergeOnTheFly) only - RotationScaleMerge
-    // never reads it - so on rotation data it would otherwise be accepted and silently do nothing.
-    if (min_image_cc > 0.0 && rotation_indexing)
-        logger.Warning("--min-image-cc is ignored for rotation data: it filters the stills merge only");
     scaling_settings.OutlierRejectNsigma(
         outlier_reject_nsigma.value_or(rotation_indexing ? REJECT_OUTLIERS_DEFAULT_NSIGMA : 0.0));