diff --git a/docs/RUGNUX.md b/docs/RUGNUX.md
index 9e66da96..0a6fe4df 100644
--- a/docs/RUGNUX.md
+++ b/docs/RUGNUX.md
@@ -202,7 +202,7 @@ Spot finding:
 
 | Option | Description |
 | --- | --- |
-| `--spot-sigma <num>` | Noise sigma level for spot finding (default: 3.0) |
+| `--spot-sigma <num>` | Noise sigma level for spot finding (default: 4.0) |
 | `--spot-threshold <num>` | Photon-count threshold for spot finding (default: 10) |
 | `--adaptive-spots` | Self-calibrating detection (**default**, stills and rotation alike): the strong-pixel threshold comes from each image's own per-resolution-ring noise instead of the fixed `--spot-threshold`, so one setting adapts across datasets (no per-dataset `--spot-threshold`/`--spot-sigma` tuning) |
 | `--no-adaptive-spots` | Turn adaptive detection off and use the fixed `--spot-threshold` / `--spot-sigma` finder |
diff --git a/rugnux/rugnux_cli.cpp b/rugnux/rugnux_cli.cpp
index 78ad2594..71c3a34b 100644
--- a/rugnux/rugnux_cli.cpp
+++ b/rugnux/rugnux_cli.cpp
@@ -61,7 +61,7 @@ void print_usage() {
     std::cout << std::endl;
 
     std::cout << "  Spot finding" << std::endl;
-    std::cout << "   --spot-sigma <num>               Noise sigma level for spot finding (default: 3.0)" << std::endl;
+    std::cout << "   --spot-sigma <num>               Noise sigma level for spot finding (default: 4.0)" << std::endl;
     std::cout << "   --spot-threshold <num>           Photon count threshold for spot finding (default: 10)" << std::endl;
     std::cout << "   --min-pix-per-spot <num>         Minimum connected strong pixels per spot. If omitted, min-pix is chosen PER IMAGE (stills indexing): the frame is indexed at min-pix 3/2/1 and the one maximising indexed count x indexed fraction is kept. Give an explicit value to force a fixed min-pix instead." << std::endl;
     std::cout << "   --adaptive-spots                 Self-calibrating detection (DEFAULT): the strong-pixel threshold comes from each image's own per-resolution-ring noise instead of the fixed --spot-threshold, so one setting adapts across datasets (no per-dataset --spot-threshold/--spot-sigma tuning)." << std::endl;
@@ -528,7 +528,7 @@ static int RunRugnux(int argc, char **argv) {
     std::optional<int64_t> space_group_number;
     std::optional<UnitCell> fixed_reference_unit_cell;
     std::optional<int64_t> max_spot_count_override;
-    float sigma_spot_finding = 3.0;
+    float sigma_spot_finding = 4.0;
     int64_t photon_count_threshold_spot_finding = 10;
     std::optional<int64_t> min_pix_per_spot;   // unset -> adaptive per image; a value -> fixed min-pix
     std::optional<bool> adaptive_spots;   // unset -> on, for both workflows