diff --git a/image_analysis/indexing/AnalyzeIndexing.cpp b/image_analysis/indexing/AnalyzeIndexing.cpp
index 3fa42078..51e884ff 100644
--- a/image_analysis/indexing/AnalyzeIndexing.cpp
+++ b/image_analysis/indexing/AnalyzeIndexing.cpp
@@ -125,8 +125,6 @@ namespace {
             const Coord w = axis->GetAxis().Normalize();
             const Coord S0 = experiment.GetScatteringVector();
             const float wedge_deg = axis->GetWedge_deg();
-            const float start_deg = axis->GetStart_deg();
-            const float inc_deg = axis->GetIncrement_deg();
 
             double sum_sq = 0.0;
             int count = 0;
@@ -135,21 +133,14 @@ namespace {
                 if (!s.indexed)
                     continue;
 
-                // Observed angle: use frame center
-                const float image_center = static_cast<float>(s.image) + 0.5f;
-                const float phi_obs_deg = start_deg + inc_deg * image_center;
-
-                // g0 at phi=0 assumption
-                const Coord g0 = astar * static_cast<float>(s.h)
-                                 + bstar * static_cast<float>(s.k)
-                                 + cstar * static_cast<float>(s.l);
+                const Coord pstar = astar * static_cast<float>(s.h) + bstar * static_cast<float>(s.k) + cstar * static_cast<float>(s.l);
 
                 // Local solve window: +/- 1 wedge (easy/robust first try)
-                const auto phi_pred_deg_opt = predict_phi_deg_local(g0, S0, w, phi_obs_deg, wedge_deg);
+                const auto phi_pred_deg_opt = predict_phi_deg_local(pstar, S0, w, 0.0, wedge_deg);
                 if (!phi_pred_deg_opt.has_value())
                     continue;
 
-                float dphi = wrap_deg_pm180(phi_obs_deg - phi_pred_deg_opt.value());
+                float dphi = wrap_deg_pm180(phi_pred_deg_opt.value());
                 sum_sq += static_cast<double>(dphi) * static_cast<double>(dphi);
                 count++;
             }