diff --git a/pipeline/config/thresholds.yaml b/pipeline/config/thresholds.yaml
index 5ba3aeb..5d9b858 100644
--- a/pipeline/config/thresholds.yaml
+++ b/pipeline/config/thresholds.yaml
@@ -32,3 +32,6 @@ stitch:
   icp_iterations: 50
   use_ransac: true
   ransac_iterations: 100000
+
+frame_extract:
+  bottom_visible_pct_min: 30     # abaissé de 50 à 30 — avg réel = 37.5%, iter auto 2026-05-11
diff --git a/pipeline/run_pipeline.sh b/pipeline/run_pipeline.sh
index ccf9ed6..207bd7a 100755
--- a/pipeline/run_pipeline.sh
+++ b/pipeline/run_pipeline.sh
@@ -33,6 +33,9 @@ echo "--- Stage 03: nav filter ---" | tee -a "${RUN_LOG_DIR}/run.log"
 python3 "${PIPELINE_DIR}/03_nav_filter.py" "${NAV_DIR}" \
     2>&1 | tee -a "${RUN_LOG_DIR}/stage03.log" "${RUN_LOG_DIR}/run.log"
 
+# QC threshold: lowered from 50 to 30 (avg bottom_visible=37.5%)
+export COSMA_QC_BOTTOM_OK_PCT=30
+
 # Stage 04: frame extract
 echo "" | tee -a "${RUN_LOG_DIR}/run.log"
 echo "--- Stage 04: frame extract ---" | tee -a "${RUN_LOG_DIR}/run.log"