diff --git a/apps/studio/config/locales/en_US.json b/apps/studio/config/locales/en_US.json
index 0de07e6..cd41d54 100644
--- a/apps/studio/config/locales/en_US.json
+++ b/apps/studio/config/locales/en_US.json
@@ -106,6 +106,7 @@
     "filter_off": "Not filtering (raw readings)",
     "ok": "OK",
     "cancel": "Cancel",
+    "save": "Save",
     "close": "Close"
   },
   "toolbar": {
@@ -214,6 +215,7 @@
     "view_arrows_pure": "Arrows",
     "view_arrows_stitched": "Arrows / Captured",
     "view_depth": "Depth map",
+    "view_depth_arrows": "Depth + arrows",
     "view_recorded": "Recorded image",
     "view_mode_tip": "Image display mode while running",
     "arrow_settings_tip": "Finger 2D presentation (orientation; display only)",
diff --git a/apps/studio/config/locales/zh_CN.json b/apps/studio/config/locales/zh_CN.json
index ef3b650..b11984b 100644
--- a/apps/studio/config/locales/zh_CN.json
+++ b/apps/studio/config/locales/zh_CN.json
@@ -106,6 +106,7 @@
     "filter_off": "未滤波（原始读数）",
     "ok": "确定",
     "cancel": "取消",
+    "save": "保存",
     "close": "关闭"
   },
   "toolbar": {
@@ -214,6 +215,7 @@
     "view_arrows_pure": "箭头",
     "view_arrows_stitched": "箭头/采集图像",
     "view_depth": "深度图",
+    "view_depth_arrows": "深度 + 箭头",
     "view_recorded": "原始图像",
     "view_mode_tip": "运行时的图像显示模式",
     "arrow_settings_tip": "手指 2D 显示方向（只影响画面）",
diff --git a/apps/studio/docs/ui-elements.json b/apps/studio/docs/ui-elements.json
index c4c6f75..b8d82cb 100644
--- a/apps/studio/docs/ui-elements.json
+++ b/apps/studio/docs/ui-elements.json
@@ -284,8 +284,8 @@
           "purpose": "write the calibration panel's coefficients (the panel's own action)" },
         { "id": "dialog_apply", "path": "sensor_dialog.btn_apply", "objectName": null, "class": "QPushButton",
           "purpose": "push the last export into the running device" },
-        { "id": "dialog_close", "path": "sensor_dialog.btn_close", "objectName": null, "class": "QPushButton",
-          "purpose": "close the dialog" }
+        { "id": "dialog_save", "path": "sensor_dialog.btn_save", "objectName": null, "class": "QPushButton",
+          "purpose": "keep the current sensor and calibration choice and dismiss the dialog" }
       ]
     }
   ],
diff --git a/apps/studio/src/orisys_studio/app_window.py b/apps/studio/src/orisys_studio/app_window.py
index 5ba280b..b534741 100644
--- a/apps/studio/src/orisys_studio/app_window.py
+++ b/apps/studio/src/orisys_studio/app_window.py
@@ -1855,21 +1855,22 @@ class StudioMainWindow(QMainWindow):
         entry = self.sensor_picker.selected_entry()
         return None if entry is None else entry.ref
 
-    def live_calibration_choice(self) -> tuple[str, Path | None, str]:
-        """``(role, file_path_or_None, device_id)`` remembered for the selected bundle.
+    def live_calibration_for(
+        self, ref: str
+    ) -> tuple[str, Path | None, str] | None:
+        """Saved live choice for one catalog ref, or ``None`` when nothing was saved.
 
-        ``file_path`` is only set for the browsed-file role; the profile default is
-        resolved when the chain opens. A missing file falls back to raw force.
+        ``None`` is not raw force: a caller that has its own default (the analysis
+        prompt) keeps that default until the sensor dialog has stored a choice.
         """
         from orisys_studio.ui.sensor_dialog import ROLE_DEFAULT, ROLE_FILE, ROLE_NONE
 
-        key = self._live_calibration_prefs_key()
         store = self.prefs.get("live_calibration")
-        if not key or not isinstance(store, dict):
-            return ROLE_NONE, None, ""
-        entry = store.get(key)
+        if not ref or not isinstance(store, dict):
+            return None
+        entry = store.get(ref)
         if not isinstance(entry, dict):
-            return ROLE_NONE, None, ""
+            return None
         role = str(entry.get("role") or ROLE_NONE)
         if role not in (ROLE_DEFAULT, ROLE_FILE, ROLE_NONE):
             role = ROLE_NONE
@@ -1882,6 +1883,20 @@ class StudioMainWindow(QMainWindow):
             path = candidate
         return role, path, str(entry.get("device_id") or "")
 
+    def live_calibration_choice(self) -> tuple[str, Path | None, str]:
+        """``(role, file_path_or_None, device_id)`` remembered for the selected bundle.
+
+        ``file_path`` is only set for the browsed-file role; the profile default is
+        resolved when the chain opens. No saved choice is raw force for a live open.
+        """
+        from orisys_studio.ui.sensor_dialog import ROLE_NONE
+
+        key = self._live_calibration_prefs_key()
+        found = None if key is None else self.live_calibration_for(key)
+        if found is None:
+            return ROLE_NONE, None, ""
+        return found
+
     def set_live_calibration_choice(
         self,
         *,
@@ -2948,6 +2963,7 @@ class StudioMainWindow(QMainWindow):
             initial_reference_frame=initial_reference_frame,
             initial_device_id=initial_device_id,
             theme=self._theme,
+            remembered_calibration=self.live_calibration_for,
         )
         if dialog.exec() != VideoAnalysisDialog.DialogCode.Accepted:
             return None
@@ -2990,6 +3006,7 @@ class StudioMainWindow(QMainWindow):
             initial_reference_frame=getattr(self, "_analysis_reference_override", None),
             lock_profile=True,
             theme=self._theme,
+            remembered_calibration=self.live_calibration_for,
         )
         if dialog.exec() != VideoAnalysisDialog.DialogCode.Accepted:
             return False
diff --git a/apps/studio/src/orisys_studio/frame_view.py b/apps/studio/src/orisys_studio/frame_view.py
index 0f2a707..8c8bf63 100644
--- a/apps/studio/src/orisys_studio/frame_view.py
+++ b/apps/studio/src/orisys_studio/frame_view.py
@@ -14,6 +14,7 @@ import numpy as np
 from orisys_app_shared.acquisition.arrows import arrow_display_scale, hex_to_bgr
 from orisys_app_shared.acquisition.image_backend import (
     DEPTH,
+    DEPTH_ARROWS,
     DomainMaskLatch,
     ImageFrame,
     plan_image,
@@ -232,7 +233,7 @@ class FrameView:
             self._last_depth_frame = frame.depth
         span = self.active_depth_span()
         self.publish_shared_depth_scale(span)
-        if mode == DEPTH:
+        if mode in (DEPTH, DEPTH_ARROWS):
             self._arrow_panel.set_depth_scale(
                 self.depth_scale_text(frame),
                 tip_key=self.depth_scale_tip_key(),
@@ -267,7 +268,7 @@ class FrameView:
             # Never substitute another picture here: a missing depth map that showed
             # the processed frame made "no depth" look like a depth reading. A draw
             # failure used to return the black base image; say so instead.
-            if mode == DEPTH and rendered is None:
+            if mode in (DEPTH, DEPTH_ARROWS) and rendered is None:
                 message = t("panels.depth_unavailable")
             elif diagnostic is not None:
                 message = t("panels.arrow_render_failed")
diff --git a/apps/studio/src/orisys_studio/ui/arrow_panel.py b/apps/studio/src/orisys_studio/ui/arrow_panel.py
index 6961741..50b0a29 100644
--- a/apps/studio/src/orisys_studio/ui/arrow_panel.py
+++ b/apps/studio/src/orisys_studio/ui/arrow_panel.py
@@ -14,6 +14,7 @@ from orisys_app_shared.acquisition.image_backend import (
     ARROW_PURE,
     ARROW_STITCHED,
     DEPTH,
+    DEPTH_ARROWS,
     ImagePlan,
 )
 from orisys_app_shared.i18n import t
@@ -32,7 +33,7 @@ from PySide6.QtWidgets import (
 from orisys_studio.ui import icons
 from orisys_studio.ui.fit_text import ShrinkableLabel
 
-VIEW_MODES = (ARROW_PURE, ARROW_STITCHED, DEPTH)
+VIEW_MODES = (ARROW_PURE, ARROW_STITCHED, DEPTH, DEPTH_ARROWS)
 #: While replaying a recording there is no optical flow to draw and no depth is
 #: stored: the panel shows the recorded frames, and nothing else.
 REPLAY_VIEW_MODES = ("recorded",)
@@ -53,6 +54,7 @@ _VIEW_LABELS = {
     ARROW_PURE: "panels.view_arrows_pure",
     ARROW_STITCHED: "panels.view_arrows_stitched",
     DEPTH: "panels.view_depth",
+    DEPTH_ARROWS: "panels.view_depth_arrows",
     "recorded": "panels.view_recorded",
 }
 _ROTATION_STEPS = (0, 90, 180, 270)
@@ -433,15 +435,17 @@ class ArrowPanel(QFrame):
         stays regardless is what the picture *is*: the plan's own line ("this recording
         stores only the raw camera image"), the depth scale, and the colour bar.
         """
-        depth = self.view_mode() == DEPTH
+        mode = self.view_mode()
+        depth = mode == DEPTH
+        overlay = mode == DEPTH_ARROWS
         modes = self.view_modes()
-        has_arrows = ARROW_PURE in modes or ARROW_STITCHED in modes
+        has_arrows = ARROW_PURE in modes or ARROW_STITCHED in modes or overlay
         explain = bool(self._show_diagnostics)
         self.scale_label.setVisible(explain and not depth and has_arrows)
         self.pipeline_label.setVisible(explain and not depth)
         self.area_label.setVisible(explain and not depth and has_arrows)
-        self.colorbar.setVisible(depth)
-        self.depth_scale_label.setVisible(depth and bool(self._depth_scale_text))
+        self.colorbar.setVisible(depth or overlay)
+        self.depth_scale_label.setVisible((depth or overlay) and bool(self._depth_scale_text))
         self.note_label.setVisible(bool(self._plan_note))
 
     def set_diagnostics_visible(self, visible: bool) -> None:
diff --git a/apps/studio/src/orisys_studio/ui/force_plots.py b/apps/studio/src/orisys_studio/ui/force_plots.py
index 810ee53..645f9da 100644
--- a/apps/studio/src/orisys_studio/ui/force_plots.py
+++ b/apps/studio/src/orisys_studio/ui/force_plots.py
@@ -1057,15 +1057,14 @@ class ForcePlotsPanel(QFrame):
         next to cards reading the live 0.0, which reads as "the replay is not
         open". Availability is decided per sample here as well, so a cursor on a
         row with no value in this unit shows a dash, never a stale number.
+
+        A zoomed window is still the cursor: the strip may name how long that
+        window is, but the big numbers stay on the sample under the playhead.
         """
         if self._mode != "browse" and not self.is_recording_source():
             return
         if not self._source_ready:
             return
-        if self._selection_active():
-            # The cards are stating the selection's peak / mean / σ; the cursor is
-            # inside that window and must not overwrite them.
-            return
         first, last = self._source.extent()
         t0 = max(first, self._cursor_t - CURSOR_READOUT_S)
         t1 = min(last, self._cursor_t + CURSOR_READOUT_S)
@@ -1095,12 +1094,11 @@ class ForcePlotsPanel(QFrame):
         self._render_value_cards()
 
     def _update_selection_readout(self) -> None:
-        """Refresh what the selection is worth: the cards, and the strip's size.
+        """Refresh the strip's window size; the cards stay on the cursor.
 
-        The per-channel numbers live on the cards (peak, then mean · σ); the strip
-        under the charts keeps only how long the selection is and how many samples
-        it holds, because that is all that fits there. The full line stays in the
-        strip's tooltip.
+        The strip under the charts keeps how long the selection is and how many
+        samples it holds. Peak / mean / σ used to sit on the value cards when the
+        window was inset; those cards now always follow the playhead.
         """
         if not self._source_ready:
             self._selection = None
@@ -1109,12 +1107,10 @@ class ForcePlotsPanel(QFrame):
             self._render_value_cards()
             return
         if not self._selection_active():
-            # Following live, or fitted to the whole session: the cards are the
-            # readout of the cursor, not of a window.
             self._selection = None
             self.stats_label.setText("")
             self.stats_label.setToolTip("")
-            self._render_value_cards()
+            self._readout_at_cursor()
             return
         t0, t1 = self._window
         stats = self._source.statistics(t0, t1, unit=self._unit)
@@ -1122,37 +1118,17 @@ class ForcePlotsPanel(QFrame):
             self._selection = None
             self.stats_label.setText(t("chart.selection_empty"))
             self.stats_label.setToolTip("")
-            self._render_value_cards()
+            self._readout_at_cursor()
             return
         self._selection = stats
-        self.stats_label.setText(
-            t(
-                "chart.selection_summary",
-                duration=f"{stats.duration_s:.2f}",
-                samples=stats.samples,
-            )
-        )
-        self.stats_label.setToolTip(self._selection_tooltip(stats))
-        self._render_value_cards()
-
-    def _selection_tooltip(self, stats) -> str:
-        """The full selection readout, for the strip's tooltip."""
-        unit = unit_display(self._unit)
-        parts = []
-        for index, label in enumerate(CHANNEL_LABELS):
-            peak = float(stats.peaks[index])
-            if not np.isfinite(peak):
-                continue
-            parts.append(
-                f"{label} 峰 {peak:.3g}{unit} · 均 {float(stats.means[index]):.3g} "
-                f"· σ {float(stats.stds[index]):.3g}"
-            )
-        return t(
-            "chart.selection",
+        summary = t(
+            "chart.selection_summary",
             duration=f"{stats.duration_s:.2f}",
             samples=stats.samples,
-            detail="   ".join(parts),
         )
+        self.stats_label.setText(summary)
+        self.stats_label.setToolTip(summary)
+        self._readout_at_cursor()
 
     def _selection_active(self) -> bool:
         """Whether the visible window is a *selection* and not the whole session.
@@ -1421,20 +1397,8 @@ class ForcePlotsPanel(QFrame):
             curve.setData([], [])
 
     def _render_value_cards(self) -> None:
-        """One card per channel: what it reads *now*, in the active unit.
-
-        While a selection is being inspected the big number is that window's peak
-        and the line under it its mean and σ — the selection statistics used to be
-        a single long line under the charts, which could not fit and pushed the
-        panel wider.
-        """
-        decimals = (
-            self.presentation.newton_decimals
-            if self._unit == "N" else self.presentation.raw_decimals
-        )
-        fmt = "{value:." + str(decimals) + "f}"
+        """One card per channel: the sample under the cursor, in the active unit."""
         unavailable = t("chart.value_unavailable")
-        selecting = self._selection
         for index, (value_label, unit_label, detail_label, value) in enumerate(
             zip(
                 self.value_labels,
@@ -1444,11 +1408,7 @@ class ForcePlotsPanel(QFrame):
             )
         ):
             available = self._available[index]
-            if selecting is not None:
-                peak = float(selecting.peaks[index])
-                available = bool(np.isfinite(peak))
-                value = peak
-            elif self.presentation.enabled:
+            if self.presentation.enabled:
                 value = self._display_values[index]
             if not available:
                 # An axis with no curve in this unit: a dash, never a raw count
@@ -1462,44 +1422,18 @@ class ForcePlotsPanel(QFrame):
                 continue
             value_label.setText(
                 format_force(value, self._unit, presentation=self.presentation)
-                if selecting is None
-                else fmt.format(value=value)
             )
-            tip = t("chart.selection_peak_tip") if selecting is not None else ""
             zero_zone = (
-                selecting is None
-                and self.presentation.enabled
+                self.presentation.enabled
                 and abs(float(value)) == 0.0
                 and index < len(self._display_suppressed)
                 and self._display_suppressed[index]
             )
-            if zero_zone:
-                tip = t("chart.zero_zone_tip")
-            value_label.setToolTip(tip)
+            value_label.setToolTip(t("chart.zero_zone_tip") if zero_zone else "")
             unit_label.setText(unit_display(self._unit))
-            if selecting is not None:
-                detail_label.setText(self._selection_detail(index))
-            elif zero_zone:
-                detail_label.setText(t("chart.zero_zone"))
-            else:
-                detail_label.setText("")
+            detail_label.setText(t("chart.zero_zone") if zero_zone else "")
         self.unit_badge.setText(unit_display(self._unit))
 
-    def _selection_detail(self, index: int) -> str:
-        """``mean · σ`` for one channel of the current selection."""
-        stats = self._selection
-        if stats is None:
-            return ""
-        mean = float(stats.means[index])
-        std = float(stats.stds[index])
-        if not np.isfinite(mean):
-            return ""
-        return t(
-            "chart.selection_detail",
-            mean=f"{mean:.4g}",
-            std=f"{std:.4g}" if np.isfinite(std) else "-",
-        )
-
     def retranslate(self) -> None:
         self.title.setText(t("panels.plots"))
         for badge, label in zip(self.channel_badges, CHANNEL_LABELS):
diff --git a/apps/studio/src/orisys_studio/ui/sensor_dialog.py b/apps/studio/src/orisys_studio/ui/sensor_dialog.py
index c5c3608..4078b35 100644
--- a/apps/studio/src/orisys_studio/ui/sensor_dialog.py
+++ b/apps/studio/src/orisys_studio/ui/sensor_dialog.py
@@ -200,13 +200,13 @@ class SensorDialog(QDialog):
         self.btn_export.clicked.connect(self._on_export)
         self.btn_apply = QPushButton()
         self.btn_apply.clicked.connect(self._on_apply)
-        self.btn_close = QPushButton()
-        self.btn_close.setProperty("compact", "true")
-        self.btn_close.clicked.connect(self.close)
+        self.btn_save = QPushButton()
+        self.btn_save.setProperty("compact", "true")
+        self.btn_save.clicked.connect(self._on_save)
         actions.addWidget(self.btn_export)
         actions.addWidget(self.btn_apply)
         actions.addStretch(1)
-        actions.addWidget(self.btn_close)
+        actions.addWidget(self.btn_save)
         root.addLayout(actions)
 
         # The picker's own changes change the calibration context, so the dialog
@@ -244,6 +244,11 @@ class SensorDialog(QDialog):
             apply()
         self.refresh()
 
+    def _on_save(self) -> None:
+        """Keep the current sensor/calibration choice and dismiss the dialog."""
+        self._persist_choice()
+        self.close()
+
     def _on_browse(self) -> None:
         chosen, _filter = QFileDialog.getOpenFileName(
             self,
@@ -554,7 +559,7 @@ class SensorDialog(QDialog):
         self.btn_export.setToolTip(t("cal.export_tip"))
         self.btn_apply.setText(t("cal.apply"))
         self.btn_apply.setToolTip(t("sensor.live_calibration_apply_tip"))
-        self.btn_close.setText(t("dialog.cancel"))
+        self.btn_save.setText(t("dialog.save"))
         self.picker.retranslate()
         self.refresh()
 
diff --git a/apps/studio/src/orisys_studio/ui/video_analysis_dialog.py b/apps/studio/src/orisys_studio/ui/video_analysis_dialog.py
index e75dacc..6031ccd 100644
--- a/apps/studio/src/orisys_studio/ui/video_analysis_dialog.py
+++ b/apps/studio/src/orisys_studio/ui/video_analysis_dialog.py
@@ -22,6 +22,7 @@ reason it cannot be used is one line, both in the language the catalog already s
 from __future__ import annotations
 
 import json
+from collections.abc import Callable
 from pathlib import Path
 
 from orisys_app_shared.analysis.bare_video import (
@@ -92,6 +93,10 @@ class VideoAnalysisDialog(QDialog):
         initial_device_id: str | None = None,
         lock_profile: bool = False,
         theme: str = "dark",
+        remembered_calibration: Callable[
+            [str], tuple[str, Path | None, str] | None
+        ]
+        | None = None,
     ) -> None:
         super().__init__(window)
         self._video = Path(video)
@@ -110,6 +115,10 @@ class VideoAnalysisDialog(QDialog):
             1 if initial_reference_frame is None else int(initial_reference_frame)
         )
         self._restore_device = str(initial_device_id or "")
+        #: ``(role, path, device_id)`` saved by the sensor dialog for a catalog ref,
+        #: or ``None`` when that bundle has no saved choice. Missing means "keep
+        #: this dialog's own default", which is not the same as an explicit raw-force choice.
+        self._remembered_calibration = remembered_calibration
         self._device_source: Path | None = None
         self._lock_profile = bool(lock_profile)
         self.setObjectName("videoAnalysisDialog")
@@ -300,7 +309,10 @@ class VideoAnalysisDialog(QDialog):
         )
         self.buttons.button(QDialogButtonBox.StandardButton.Ok).setEnabled(not blocked)
         self._refresh_time_label()
+        device_id = self._apply_remembered_calibration()
         self._sync_device_row()
+        if device_id:
+            self.device_edit.setText(device_id)
 
     def _refresh_calibrations(self, *, custom: Path | None) -> None:
         """The calibration field: the profile's default, raw force, or a chosen file."""
@@ -328,6 +340,32 @@ class VideoAnalysisDialog(QDialog):
         self.calibration_combo.blockSignals(False)
         self._sync_device_row()
 
+    def _apply_remembered_calibration(self) -> str:
+        """Select the sensor dialog's saved choice for this profile.
+
+        Returns a device serial to put back after the row sync, or ``""`` when
+        there is nothing saved (the combo keeps the profile default or raw force).
+        """
+        entry = self.entry()
+        memory = self._remembered_calibration
+        if entry is None or not callable(memory):
+            return ""
+        found = memory(entry.ref)
+        if found is None:
+            return ""
+        role, path, device_id = found
+        if role == ROLE_FILE and path is not None and Path(path).is_file():
+            self.select_calibration(Path(path))
+            return str(device_id or "")
+        if role == ROLE_NONE:
+            self.select_calibration(None)
+            return ""
+        if role == ROLE_DEFAULT:
+            index = self.calibration_combo.findData(ROLE_DEFAULT)
+            if index >= 0:
+                self.calibration_combo.setCurrentIndex(index)
+        return ""
+
     def _chosen_calibration(self) -> Path | None:
         role = str(self.calibration_combo.currentData() or "")
         entry = self.entry()
diff --git a/apps/studio/tests/test_live_calibration_dialog.py b/apps/studio/tests/test_live_calibration_dialog.py
index 853a1f1..85c0505 100644
--- a/apps/studio/tests/test_live_calibration_dialog.py
+++ b/apps/studio/tests/test_live_calibration_dialog.py
@@ -6,11 +6,13 @@ import json
 from pathlib import Path
 
 import pytest
+from orisys_app_shared.analysis.bare_video import VideoFacts
 from orisys_app_shared.i18n import t
 from orisys_app_shared.sensors import scan_sensor_catalog
 from orisys_studio.ui import sensor_picker as picker_module
 from orisys_studio.ui.sensor_dialog import ROLE_DEFAULT, ROLE_FILE, ROLE_NONE, SensorDialog
 from orisys_studio.ui.sensor_picker import SensorPickerWidget
+from orisys_studio.ui.video_analysis_dialog import VideoAnalysisDialog
 from PySide6.QtWidgets import QWidget
 
 CONFIG = {
@@ -319,3 +321,71 @@ def test_apply_while_running_queues_set_pending_calibration(make_window, tmp_pat
     window.apply_live_calibration_choice()
     assert pending == []
     assert window.statusBar().currentMessage() == t("sensor.live_calibration_remembered")
+
+
+def _facts(path: Path) -> VideoFacts:
+    return VideoFacts(path=path, frame_count=4, fps=10.0, width=8, height=8)
+
+
+def test_analysis_prompt_defaults_to_the_saved_sensor_file(make_window, tmp_path):
+    """The file saved from the sensor dialog is the analysis prompt's starting choice."""
+    window = make_window()
+    entry = window.sensor_picker.selected_entry()
+    assert entry is not None
+    assert window.live_calibration_for(entry.ref) is None
+    cal = tmp_path / "picked.json"
+    cal.write_text("{}", encoding="utf-8")
+    window.set_live_calibration_choice(role=ROLE_FILE, path=cal)
+    dialog = VideoAnalysisDialog(
+        video=tmp_path / "clip.mp4",
+        facts=_facts(tmp_path / "clip.mp4"),
+        catalog=scan_sensor_catalog(),
+        window=window,
+        initial_profile=entry.ref,
+        remembered_calibration=window.live_calibration_for,
+    )
+    try:
+        assert dialog.calibration_combo.currentData() == ROLE_FILE
+        assert dialog._chosen_calibration() == cal
+    finally:
+        dialog.deleteLater()
+
+
+def test_analysis_prompt_keeps_its_default_until_a_choice_is_saved(
+    make_window, tmp_path
+):
+    window = make_window()
+    dialog = VideoAnalysisDialog(
+        video=tmp_path / "clip.mp4",
+        facts=_facts(tmp_path / "clip.mp4"),
+        catalog=scan_sensor_catalog(),
+        window=window,
+        initial_profile="shipped/box",
+        remembered_calibration=window.live_calibration_for,
+    )
+    try:
+        assert dialog.calibration_combo.currentData() == ROLE_DEFAULT
+    finally:
+        dialog.deleteLater()
+
+
+def test_a_reopened_analysis_setup_still_beats_the_saved_file(make_window, tmp_path):
+    window = make_window()
+    entry = window.sensor_picker.selected_entry()
+    assert entry is not None
+    cal = tmp_path / "picked.json"
+    cal.write_text("{}", encoding="utf-8")
+    window.set_live_calibration_choice(role=ROLE_FILE, path=cal)
+    dialog = VideoAnalysisDialog(
+        video=tmp_path / "clip.mp4",
+        facts=_facts(tmp_path / "clip.mp4"),
+        catalog=scan_sensor_catalog(),
+        window=window,
+        initial_profile=entry.ref,
+        prefer_no_calibration=True,
+        remembered_calibration=window.live_calibration_for,
+    )
+    try:
+        assert dialog.calibration_combo.currentData() == ROLE_NONE
+    finally:
+        dialog.deleteLater()
diff --git a/apps/studio/tests/test_scene3d_overlays.py b/apps/studio/tests/test_scene3d_overlays.py
index 31ef6f1..1c65281 100644
--- a/apps/studio/tests/test_scene3d_overlays.py
+++ b/apps/studio/tests/test_scene3d_overlays.py
@@ -120,9 +120,9 @@ def test_2d_3d_flow_sample_points_match() -> None:
         composed = composer.compose(
             assets, _depth_frame(assets, flow=flow), settings
         )
-        arrows_3d = (
-            0 if composed.flow_arrows is None else int(composed.flow_arrows.origins.shape[0])
-        )
+        arrows = None if composed.flow_arrows is None else composed.flow_arrows.lengths
+        # Positive lengths are arrows. Negative lengths are the idle points.
+        arrows_3d = 0 if arrows is None else int(np.count_nonzero(arrows > 0.0))
         # Exactly what the 2D canvas draws from: ``draw_arrow_display`` calls
         # ``select_flow_samples`` with the policy the window passes it, and draws the
         # samples the flag marks active.
diff --git a/apps/studio/tests/test_ui_smoke.py b/apps/studio/tests/test_ui_smoke.py
index 9958231..fd51bb5 100644
--- a/apps/studio/tests/test_ui_smoke.py
+++ b/apps/studio/tests/test_ui_smoke.py
@@ -1741,7 +1741,12 @@ def test_the_replay_view_loads_a_recording_and_scrubs_it(make_window, replay_rec
     assert panel.mode() == "follow"
     assert window.toolbar.run_role() == "acquire", "the rail kept the transport"
     assert window.toolbar.btn_run.text() == t("toolbar.run_label")
-    assert window.arrow_panel.view_modes() == ("arrows_pure", "arrows_stitched", "depth")
+    assert window.arrow_panel.view_modes() == (
+        "arrows_pure",
+        "arrows_stitched",
+        "depth",
+        "depth_arrows",
+    )
     assert "raw_0001" not in window.toolbar.source_summary.text(), (
         "the replay's video is still named in the live view"
     )
@@ -2747,14 +2752,15 @@ def test_a_recording_without_a_video_says_it_cannot_be_played(make_window, recor
 # ------------------------------------------- selection readout and notices
 
 
-def test_a_selection_moves_its_statistics_onto_the_value_cards(make_window):
-    """The per-channel line under the charts did not fit; the cards hold it now.
+def test_a_zoomed_window_keeps_the_cursor_on_the_value_cards(make_window):
+    """Zooming names the window in the strip; the cards stay on the playhead.
 
-    Selecting a window makes the big number that window's peak and the line under
-    it its mean · σ. The strip keeps only how big the selection is, and leaving
-    the selection puts the cursor readout back.
+    Selecting a window used to put that window's peak and mean · σ on the cards.
+    The big numbers are the sample under the cursor again; the strip keeps only
+    how big the selection is.
     """
     from orisys_app_shared.i18n import t
+    from orisys_studio.ui.force_plots import format_force
 
     window, stuck = _running_window(make_window)
     window.toolbar.units_combo.setCurrentIndex(0)  # newton
@@ -2768,6 +2774,7 @@ def test_a_selection_moves_its_statistics_onto_the_value_cards(make_window):
     assert plots.stats_label.text() == ""
     assert plots.value_details[0].text() == "", "a live reading carries a mean line"
 
+    plots.set_cursor(2.0)
     plots.set_window(1.0, 3.0)
     assert plots.mode() == "browse"
     assert plots._selection is not None, "the window was not read as a selection"
@@ -2777,17 +2784,17 @@ def test_a_selection_moves_its_statistics_onto_the_value_cards(make_window):
     assert t("chart.selection_summary", duration="1", samples=2)[:4] in summary or (
         "选区" in summary or "Selection" in summary
     ), summary
-    # The numbers a reader cannot fit in the strip are on the cards instead.
-    expected_peak = float(plots._selection.peaks[0])
-    expected = f"{expected_peak:.2f}"
-    assert plots.value_labels[0].text() == expected, (
-        f"the FN card is not the selection's peak: {plots.value_labels[0].text()!r}"
+    assert "峰" not in summary and "均" not in summary, summary
+
+    expected = format_force(
+        plots._display_values[0], plots.unit(), presentation=plots.presentation
+    )
+    assert plots.value_labels[0].text() == expected, (
+        f"the FN card is not the cursor sample: {plots.value_labels[0].text()!r}"
+    )
+    assert plots.value_details[0].text() == "", (
+        f"the card still carries a mean line: {plots.value_details[0].text()!r}"
     )
-    detail = plots.value_details[0].text()
-    assert detail and detail != "", detail
-    assert f"{float(plots._selection.means[0]):.4g}" in detail, (detail, plots._selection.means[0])
-    assert "均" in detail or "mean" in detail, detail
-    assert plots.value_labels[0].toolTip(), "the peak is not explained anywhere"
 
     # "Whole session" is the default fit, so it is not a selection.
     plots.show_all()
diff --git a/apps/studio/tools/ui_check.py b/apps/studio/tools/ui_check.py
index 18fdffb..8801be3 100644
--- a/apps/studio/tools/ui_check.py
+++ b/apps/studio/tools/ui_check.py
@@ -2775,9 +2775,8 @@ def main() -> int:
         plots.overview_curve.getData()[0].size > 0,
         "the whole-session overview strip is empty",
     )
-    # A window narrower than the session is a selection: its peak becomes the big
-    # number on each card and its mean/σ the line under it, while the strip keeps
-    # only the size of the selection (the long per-channel line did not fit).
+    # A window narrower than the session is a selection in the strip only: the
+    # cards stay on the sample under the cursor.
     check(plots._selection is not None, "zooming in did not record a selection")
     summary = plots.stats_label.text()
     check(summary != "", "the strip does not state the size of the selection")
@@ -2789,34 +2788,25 @@ def main() -> int:
         "选区" in summary or "Selection" in summary,
         f"the strip does not say that the numbers describe a selection: {summary!r}",
     )
-    expected_peak = float(plots._selection.peaks[0])
-    peak_text = (
-        f"{expected_peak:.3f}" if plots.unit() == "N" else f"{expected_peak:.1f}"
+    from orisys_studio.ui.force_plots import format_force
+
+    expected_cursor = format_force(
+        plots._display_values[0], plots.unit(), presentation=plots.presentation
     )
     check(
-        plots.value_labels[0].text() == peak_text,
-        f"the FN card is not the selection's peak: {plots.value_labels[0].text()!r}",
+        plots.value_labels[0].text() == expected_cursor,
+        f"the FN card is not the cursor sample: {plots.value_labels[0].text()!r}",
     )
     check(
-        plots.value_details[0].text() != ""
-        and ("均" in plots.value_details[0].text() or "mean" in plots.value_details[0].text()),
-        f"the card does not state the selection's mean: "
-        f"{plots.value_details[0].text()!r}",
+        plots.value_details[0].text() == "",
+        f"the card still carries a mean line: {plots.value_details[0].text()!r}",
     )
-    for card, label, detail in zip(
-        plots.value_cards, plots.value_labels, plots.value_details
-    ):
-        check(
-            detail.width() >= detail.sizeHint().width(),
-            f"the selection detail line is clipped: "
-            f"{detail.width()} < {detail.sizeHint().width()}",
-        )
-    # Leaving the selection hands the cards back to the cursor readout.
+    # Leaving the selection clears the strip; the cards stay a cursor readout.
     plots.follow_latest()
     check(plots._selection is None, "the selection survived 'back to latest'")
     check(
         plots.value_details[0].text() == "",
-        f"the mean line survived leaving the selection: "
+        f"a detail line appeared after leaving the selection: "
         f"{plots.value_details[0].text()!r}",
     )
 
@@ -3673,7 +3663,12 @@ def main() -> int:
         f"{replay_window.toolbar.source_summary.text()!r}",
     )
     check(
-        replay_window.arrow_panel.view_modes() == ("arrows_pure", "arrows_stitched", "depth"),
+        replay_window.arrow_panel.view_modes() == (
+            "arrows_pure",
+            "arrows_stitched",
+            "depth",
+            "depth_arrows",
+        ),
         "the 2D panel did not return to its live views",
     )
     check(
diff --git a/shared/src/orisys_app_shared/acquisition/image_backend.py b/shared/src/orisys_app_shared/acquisition/image_backend.py
index b66f962..04051db 100644
--- a/shared/src/orisys_app_shared/acquisition/image_backend.py
+++ b/shared/src/orisys_app_shared/acquisition/image_backend.py
@@ -47,9 +47,10 @@ from orisys_app_shared.acquisition.models import ensure_bgr
 ARROW_PURE = "arrows_pure"
 ARROW_STITCHED = "arrows_stitched"
 DEPTH = "depth"
+DEPTH_ARROWS = "depth_arrows"
 RECORDED = "recorded"
 
-DERIVED_MODES = (ARROW_PURE, ARROW_STITCHED, DEPTH)
+DERIVED_MODES = (ARROW_PURE, ARROW_STITCHED, DEPTH, DEPTH_ARROWS)
 ALL_MODES = (*DERIVED_MODES, RECORDED)
 
 #: Where a frame came from. Only used for wording and for the recording; the modes
@@ -294,6 +295,8 @@ class ImagePlan:
             return "flow"
         if wanted == DEPTH and not self.has_depth():
             return "depth"
+        if wanted == DEPTH_ARROWS and not self.has_depth() and not self.has_flow():
+            return "depth"
         return None
 
     def has_flow(self) -> bool:
@@ -374,6 +377,52 @@ def plan_image(frame: ImageFrame) -> ImagePlan:
     )
 
 
+def _orient_drawn(drawn: np.ndarray, turn: str) -> np.ndarray:
+    """Apply a display orientation without dropping a draw-failure mark."""
+    diagnostic = getattr(drawn, "frame_diagnostic", None)
+    oriented = apply_orientation(drawn, turn)
+    if diagnostic is None:
+        return oriented
+    return carry_frame_diagnostic(oriented, diagnostic)
+
+
+def _draw_flow(
+    frame: ImageFrame,
+    base: np.ndarray,
+    *,
+    background: str,
+    theme: str,
+    draw_style: str,
+    domain_mask: np.ndarray | None,
+    arrow_policy,
+    canvas_bgr: Sequence[int] | None = None,
+    sdk_result: bool | None = None,
+) -> np.ndarray:
+    """Arrows on ``base``, using the same painter the pure-arrow views use."""
+    if sdk_result is None:
+        box_style = not str(draw_style).lower().startswith("f")
+        sdk_result = (
+            box_style
+            and str(frame.source or "") in RESULT_SOURCES
+            and uses_sdk_box_grid(arrow_policy)
+        )
+    flow = frame.flow
+    if sdk_result and flow is not None:
+        flow = np.nan_to_num(np.asarray(flow, dtype=np.float64), nan=0.0)
+    return draw_arrow_display(
+        base,
+        flow,
+        background=background,
+        canvas_bgr=canvas_bgr,
+        draw_style=draw_style,
+        shared_painter=str(frame.source or "") in RESULT_SOURCES and not sdk_result,
+        valid_mask=frame.valid_mask,
+        domain_mask=domain_mask,
+        colormap=flow_colormap(theme),
+        policy=arrow_policy,
+    )
+
+
 def render_image(
     frame: ImageFrame,
     plan: ImagePlan | None = None,
@@ -418,59 +467,55 @@ def render_image(
     wanted = plan.resolve(mode)
     boundary = frame.valid_mask if domain_mask is None else domain_mask
     turn = normalise_orientation(orientation) if wanted != RECORDED else ORIENTATION_IDENTITY
-    if wanted == DEPTH:
-        # Never substitute another picture for a missing depth map: that made "no
-        # depth" look like a depth reading. The panel says so instead.
-        if frame.depth_valid is False:
-            return None
+    depth_image = None
+    if wanted in (DEPTH, DEPTH_ARROWS) and frame.depth_valid is not False:
         depth_image = depth_map_to_bgr(
             frame.depth,
             flow_colormap(theme),
             value_range=depth_range,
             invalid_mask=boundary,
         )
+    if wanted == DEPTH:
+        # Never substitute another picture for a missing depth map: that made "no
+        # depth" look like a depth reading. The panel says so instead.
         if depth_image is None:
             return None
         return apply_orientation(depth_image, turn)
+    if wanted == DEPTH_ARROWS:
+        if depth_image is None:
+            wanted = ARROW_PURE
+        elif frame.flow is None or frame.flow_valid is False:
+            return apply_orientation(depth_image, turn)
+        else:
+            drawn = _draw_flow(
+                frame,
+                depth_image,
+                background="captured",
+                theme=theme,
+                draw_style=draw_style,
+                domain_mask=domain_mask,
+                arrow_policy=arrow_policy,
+            )
+            return _orient_drawn(drawn, turn)
     if frame.image_bgr is None:
         return None
     if wanted in (ARROW_PURE, ARROW_STITCHED):
         if frame.flow is None or frame.flow_valid is False:
             # The base picture with no arrows, and the plan's ``missing`` says why.
             return apply_orientation(ensure_bgr(np.asarray(frame.image_bgr)), turn)
-        # A recovered field is finite only at the cells the pass stored. The shared
-        # painter draws those cells; the SDK painter walks its own grid and finds
-        # nothing wherever that grid and the stored cells disagree. A box result whose
-        # grid *is* the SDK grid is the exception: fill the gaps with zero (the cells
-        # the painter does not read) and call the same ``draw_arrows`` live uses.
-        box_style = not str(draw_style).lower().startswith("f")
-        sdk_result = (
-            box_style
-            and str(frame.source or "") in RESULT_SOURCES
-            and uses_sdk_box_grid(arrow_policy)
-        )
-        flow = frame.flow
-        if sdk_result:
-            flow = np.nan_to_num(np.asarray(flow, dtype=np.float64), nan=0.0)
-        drawn = draw_arrow_display(
+        # A recovered field is finite only at the cells the pass stored. ``_draw_flow``
+        # fills a box result's gaps with zero and keeps the shared painter otherwise.
+        drawn = _draw_flow(
+            frame,
             frame.image_bgr,
-            flow,
             background="captured" if wanted == ARROW_STITCHED else "pure_color",
-            canvas_bgr=canvas_bgr,
+            theme=theme,
             draw_style=draw_style,
-            shared_painter=str(frame.source or "") in RESULT_SOURCES and not sdk_result,
-            valid_mask=frame.valid_mask,
+            canvas_bgr=canvas_bgr,
             domain_mask=domain_mask,
-            colormap=flow_colormap(theme),
-            policy=arrow_policy,
+            arrow_policy=arrow_policy,
         )
-        # Orientation may rebuild the array; keep the draw failure on the result so the
-        # panel can say so instead of showing a silent black canvas.
-        diagnostic = getattr(drawn, "frame_diagnostic", None)
-        oriented = apply_orientation(drawn, turn)
-        if diagnostic is None:
-            return oriented
-        return carry_frame_diagnostic(oriented, diagnostic)
+        return _orient_drawn(drawn, turn)
     # ``recorded``: the frame is the picture, with nothing drawn over it — and the
     # camera's own orientation, which no domain convention applies to.
     return ensure_bgr(np.asarray(frame.image_bgr))
diff --git a/shared/src/orisys_app_shared/scene3d/composer.py b/shared/src/orisys_app_shared/scene3d/composer.py
index 8137825..0fc28b8 100644
--- a/shared/src/orisys_app_shared/scene3d/composer.py
+++ b/shared/src/orisys_app_shared/scene3d/composer.py
@@ -282,11 +282,10 @@ class SceneComposer:
                     frame.flow_valid_mask,
                     policy,
                 )
-                # The selector returns every candidate location plus an ``active`` flag;
-                # this figure draws the active ones, which is what it drew before the
-                # split (the selector used to filter and this figure drew the lot).
+                # Inactive candidates are grey points; active ones are coloured arrows.
+                # Same samples the 2D canvas paints, including the quiet ones.
                 flow_arrows, extra = build_flow_overlay(
-                    samples.active_only(),
+                    samples,
                     mapping,
                     style=policy,
                     normal_offset_m=mesh_span_from_mapping(mapping) * 0.002,
diff --git a/shared/src/orisys_app_shared/scene3d/overlays.py b/shared/src/orisys_app_shared/scene3d/overlays.py
index 521ce0c..04f33e2 100644
--- a/shared/src/orisys_app_shared/scene3d/overlays.py
+++ b/shared/src/orisys_app_shared/scene3d/overlays.py
@@ -19,6 +19,14 @@ from orisys_app_shared.scene3d.contracts import (
     error,
     freeze,
 )
+from orisys_app_shared.acquisition.arrows import (
+    FLOW_IDLE_HEX,
+    FLOW_MAGNITUDE_RANGE,
+    hex_to_bgr,
+    magnitude_to_ramp_index,
+    ramp_for_theme,
+    ramp_rgba_table,
+)
 from orisys_app_shared.scene3d.visual_policy import FlowSamples, VisualPolicy
 
 ForceStrengthMode = Literal["log", "power", "linear"]
@@ -43,8 +51,11 @@ class ContactArrowStyle:
 
 DEFAULT_CONTACT_ARROW_STYLE = ContactArrowStyle()
 
-FLOW_TAIL_RGBA = (38 / 255.0, 235 / 255.0, 89 / 255.0, 0.85)
-FLOW_HEAD_RGBA = (13 / 255.0, 115 / 255.0, 31 / 255.0, 0.95)
+
+def _idle_rgba() -> np.ndarray:
+    """The 2D idle-dot tint, as linear RGBA. Same hex, so a quiet sample matches."""
+    blue, green, red = hex_to_bgr(FLOW_IDLE_HEX)
+    return np.asarray((red, green, blue, 230), dtype=np.float32) / 255.0
 
 
 def _empty_arrows(kind: str) -> ArrowInstances:
@@ -190,6 +201,75 @@ def flow_arrow_shaft_radius_m(
     return float(np.clip(radius, span * low, span * high))
 
 
+def _merge_arrows(first: ArrowInstances, second: ArrowInstances) -> ArrowInstances:
+    """One flow batch: coloured arrows, then the grey idle points."""
+    if int(first.origins.shape[0]) == 0:
+        return second
+    if int(second.origins.shape[0]) == 0:
+        return first
+    return ArrowInstances(
+        origins=freeze(np.vstack([first.origins, second.origins]), dtype=np.float32),
+        directions=freeze(
+            np.vstack([first.directions, second.directions]), dtype=np.float32
+        ),
+        lengths=freeze(np.concatenate([first.lengths, second.lengths]), dtype=np.float32),
+        colors=freeze(np.vstack([first.colors, second.colors]), dtype=np.float32),
+        kind="flow",
+        shaft_radius_m=float(first.shaft_radius_m or second.shaft_radius_m),
+    )
+
+
+def _idle_flow_points(
+    samples: FlowSamples,
+    mapping: SurfaceMapping,
+    *,
+    normal_offset_m: float,
+) -> ArrowInstances:
+    """A fixed grey point at every candidate the threshold has not turned on.
+
+    A negative length is the mesh builder's mark for that point (see
+    :func:`arrow_instances_to_mesh`). The colour is the 2D idle dot, not the ramp.
+    """
+    active = np.asarray(samples.active, dtype=bool)
+    if active.shape != samples.rows.shape or not np.any(~active):
+        return _empty_arrows("flow")
+    rows = np.asarray(samples.rows, dtype=np.int32)[~active]
+    cols = np.asarray(samples.cols, dtype=np.int32)[~active]
+    h, w = mapping.shape_hw
+    inside = (rows >= 0) & (rows < h) & (cols >= 0) & (cols < w)
+    if not np.any(inside):
+        return _empty_arrows("flow")
+    rows = rows[inside]
+    cols = cols[inside]
+    valid = np.asarray(mapping.valid, dtype=bool)
+    keep = valid[rows, cols]
+    if not np.any(keep):
+        return _empty_arrows("flow")
+    rows = rows[keep]
+    cols = cols[keep]
+    positions = np.asarray(mapping.positions_sensor_m, dtype=np.float64)
+    normals = np.asarray(mapping.normals_sensor, dtype=np.float64)
+    origins = positions[rows, cols].copy()
+    directions = normals[rows, cols].copy()
+    norms = np.linalg.norm(directions, axis=1)
+    bad = norms < 1e-8
+    directions[bad] = (0.0, 0.0, 1.0)
+    norms = np.where(bad, 1.0, norms)
+    directions = directions / norms[:, None]
+    if normal_offset_m:
+        origins = origins + normal_offset_m * directions
+    radius = flow_arrow_shaft_radius_m(mapping)
+    count = int(rows.size)
+    return ArrowInstances(
+        origins=freeze(origins, dtype=np.float32),
+        directions=freeze(directions, dtype=np.float32),
+        lengths=freeze(np.full(count, -radius, dtype=np.float32), dtype=np.float32),
+        colors=freeze(np.tile(_idle_rgba(), (count, 1)), dtype=np.float32),
+        kind="flow",
+        shaft_radius_m=radius,
+    )
+
+
 def build_flow_overlay(
     samples: FlowSamples,
     mapping: SurfaceMapping,
@@ -197,7 +277,31 @@ def build_flow_overlay(
     style: VisualPolicy | None = None,
     normal_offset_m: float = 0.0,
 ) -> tuple[ArrowInstances, tuple[Diagnostic, ...]]:
-    """Map shared UV flow samples onto the sensing surface."""
+    """Map shared UV flow samples onto the sensing surface.
+
+    Inactive candidates are grey points. Active ones are arrows coloured by the
+    same magnitude ramp the 2D canvas uses.
+    """
+    points = _idle_flow_points(
+        samples, mapping, normal_offset_m=normal_offset_m
+    )
+    arrows, diags = _active_flow_overlay(
+        samples.active_only(),
+        mapping,
+        style=style,
+        normal_offset_m=normal_offset_m,
+    )
+    return _merge_arrows(arrows, points), diags
+
+
+def _active_flow_overlay(
+    samples: FlowSamples,
+    mapping: SurfaceMapping,
+    *,
+    style: VisualPolicy | None = None,
+    normal_offset_m: float = 0.0,
+) -> tuple[ArrowInstances, tuple[Diagnostic, ...]]:
+    """Arrows for samples that cleared the flow threshold."""
     del style  # lengths come from UV tip deltas projected into scene metres
     if samples.rows.size == 0:
         return _empty_arrows("flow"), ()
@@ -216,6 +320,7 @@ def build_flow_overlay(
 
     rows = np.asarray(samples.rows, dtype=np.int32)
     cols = np.asarray(samples.cols, dtype=np.int32)
+    magnitude = np.asarray(samples.magnitude, dtype=np.float64)
     end_x = np.clip(np.round(cols + samples.dx).astype(np.int32), 0, w - 1)
     end_y = np.clip(np.round(rows + samples.dy).astype(np.int32), 0, h - 1)
 
@@ -232,6 +337,7 @@ def build_flow_overlay(
 
     rows = rows[inside]
     cols = cols[inside]
+    magnitude = magnitude[inside]
     end_x = end_x[inside]
     end_y = end_y[inside]
     origins = positions[rows, cols].copy()
@@ -248,13 +354,15 @@ def build_flow_overlay(
     origins = origins[keep]
     vectors = vectors[keep]
     lengths = lengths[keep]
+    magnitude = magnitude[keep]
     directions = vectors / lengths[:, None]
 
-    colors = np.tile(np.asarray(FLOW_TAIL_RGBA, dtype=np.float32), (len(origins), 1))
-    # Stronger arrows tip toward the head colour.
-    t = np.clip(lengths / max(float(np.percentile(lengths, 95)), 1e-9), 0.0, 1.0)
-    head = np.asarray(FLOW_HEAD_RGBA, dtype=np.float32)
-    colors = colors * (1.0 - t)[:, None] + head * t[:, None]
+    # Same ramp index the 2D canvas asks for, so an active arrow is the same colour
+    # in both views. Quiet samples never reach here: they are the grey points.
+    index = magnitude_to_ramp_index(magnitude, value_range=FLOW_MAGNITUDE_RANGE)
+    table = ramp_rgba_table(ramp_for_theme("dark")).reshape(-1, 4).astype(np.float32)
+    colors = table[index] / 255.0
+    colors[:, 3] = 0.9
 
     return (
         ArrowInstances(
@@ -499,6 +607,35 @@ def _cylinder_template(resolution: int = 8) -> tuple[np.ndarray, np.ndarray]:
     )
 
 
+def _point_template() -> tuple[np.ndarray, np.ndarray]:
+    """Unit octahedron. A negative arrow length asks the mesh builder for one of these."""
+    vertices = np.asarray(
+        [
+            [1.0, 0.0, 0.0],
+            [-1.0, 0.0, 0.0],
+            [0.0, 1.0, 0.0],
+            [0.0, -1.0, 0.0],
+            [0.0, 0.0, 1.0],
+            [0.0, 0.0, -1.0],
+        ],
+        dtype=np.float64,
+    )
+    triangles = np.asarray(
+        [
+            [0, 2, 4],
+            [2, 1, 4],
+            [1, 3, 4],
+            [3, 0, 4],
+            [2, 0, 5],
+            [1, 2, 5],
+            [3, 1, 5],
+            [0, 3, 5],
+        ],
+        dtype=np.int32,
+    )
+    return vertices, triangles
+
+
 def _cone_template(resolution: int = 8) -> tuple[np.ndarray, np.ndarray]:
     """Unit-radius cone with apex at z=1 and base at z=0."""
     angles = np.linspace(0.0, 2.0 * np.pi, resolution, endpoint=False)
@@ -534,6 +671,7 @@ def arrow_instances_to_mesh(
 
     cyl_v, cyl_t = _cylinder_template()
     cone_v, cone_t = _cone_template()
+    point_v, point_t = _point_template()
     origins = np.asarray(arrows.origins, dtype=np.float64)
     directions = np.asarray(arrows.directions, dtype=np.float64)
     lengths = np.asarray(arrows.lengths, dtype=np.float64)
@@ -544,7 +682,8 @@ def arrow_instances_to_mesh(
         else np.ones(count, dtype=np.float64)
     )
 
-    mean_length = float(np.mean(lengths)) if count else 1.0
+    positive = lengths[lengths > 0.0]
+    mean_length = float(np.mean(positive)) if positive.size else 1.0
     # An explicit stroke radius wins over the proportional one: see
     # ``flow_arrow_shaft_radius_m`` for why a flow arrow cannot use a fraction of its
     # own length. The contact arrow keeps the proportional template.
@@ -561,11 +700,20 @@ def arrow_instances_to_mesh(
     offset = 0
     for i in range(count):
         length = float(lengths[i])
+        origin = origins[i]
+        radius = base_radius * float(max(thickness[i], 0.05))
+        if length < 0.0:
+            # Idle sample: a fixed grey point, not an arrow. ``length`` is unused;
+            # the radius is the same stroke the active arrows use.
+            verts = point_v * radius + origin
+            parts_v.append(verts)
+            parts_t.append(point_t + offset)
+            parts_c.append(np.tile(colors[i], (len(verts), 1)))
+            offset += len(verts)
+            continue
         if length <= 1e-9:
             continue
         direction = directions[i]
-        origin = origins[i]
-        radius = base_radius * float(max(thickness[i], 0.05))
         rotation = _rotation_matrix_z_to(direction)
         # Tail: 75% cylinder, head: 25% cone.
         tail_len = length * 0.75
diff --git a/shared/tests/test_image_backend.py b/shared/tests/test_image_backend.py
index 5e8a007..713f85a 100644
--- a/shared/tests/test_image_backend.py
+++ b/shared/tests/test_image_backend.py
@@ -36,12 +36,22 @@ def test_a_live_frame_offers_the_derived_modes_and_needs_no_note():
     plan = backend.plan_image(
         backend.ImageFrame(_image(), flow=_flow(), depth=np.ones((12, 16)))
     )
-    assert plan.available_modes == ("arrows_pure", "arrows_stitched", "depth")
+    assert plan.available_modes == ("arrows_pure", "arrows_stitched", "depth", "depth_arrows")
     assert plan.default_mode == "arrows_pure"
     assert plan.missing == ()
     assert plan.note_key == ""
 
 
+def test_depth_arrows_draws_the_flow_on_the_depth_picture():
+    depth = np.linspace(0.0, 1.0, 12 * 16, dtype=np.float32).reshape(12, 16)
+    frame = backend.ImageFrame(_image(), flow=_flow(), depth=depth)
+    plain = backend.render_image(frame, mode="depth", draw_style="finger")
+    over = backend.render_image(frame, mode="depth_arrows", draw_style="finger")
+    assert plain is not None and over is not None
+    assert over.shape == plain.shape
+    assert not np.array_equal(over, plain)
+
+
 def test_a_recorded_frame_is_raw_and_says_so():
     """No flow and no depth: the frame *is* the picture, and the note explains it."""
     plan = backend.plan_image(backend.ImageFrame(_image(), source=backend.SOURCE_REPLAY))
@@ -723,9 +733,12 @@ def test_hiding_the_idle_dots_leaves_the_3d_figure_where_it_was():
         f"{int(active.sum())} active of {samples.rows.size} candidates"
     )
     assert overlay_on is not None and overlay_off is not None
-    assert overlay_on.origins.shape[0] == int(active.sum()), (
+    assert int(np.count_nonzero(overlay_on.lengths > 0.0)) == int(active.sum()), (
         "the 3D overlay is not drawing the active samples the 2D canvas draws"
     )
+    assert int(np.count_nonzero(overlay_on.lengths < 0.0)) > 0, (
+        "inactive samples are not drawn as grey points"
+    )
     assert np.array_equal(overlay_on.origins, overlay_off.origins)
     assert np.array_equal(overlay_on.directions, overlay_off.directions)
     assert not np.array_equal(dots_on, dots_off), "the switch changed nothing to hide"
diff --git a/shared/tests/test_overlays.py b/shared/tests/test_overlays.py
index 2e4404c..53cf038 100644
--- a/shared/tests/test_overlays.py
+++ b/shared/tests/test_overlays.py
@@ -3,6 +3,7 @@
 from __future__ import annotations
 
 import numpy as np
+import pytest
 from orisys_app_shared.scene3d.overlays import (
     arrow_instances_to_mesh,
     build_flow_overlay,
@@ -10,7 +11,7 @@ from orisys_app_shared.scene3d.overlays import (
     force_visual_strength,
 )
 from orisys_app_shared.scene3d.synthetic import poc_scene
-from orisys_app_shared.scene3d.visual_policy import VisualPolicy, select_flow_samples
+from orisys_app_shared.scene3d.visual_policy import FlowSamples, VisualPolicy, select_flow_samples
 
 
 def test_force_visual_strength_is_capped() -> None:
@@ -58,6 +59,30 @@ def test_flow_and_normal_overlays_on_poc_mapping() -> None:
     assert colors.shape[0] == positions.shape[0]
 
 
+def test_an_inactive_sample_is_a_grey_point_and_an_active_one_is_an_arrow() -> None:
+    assets = poc_scene()
+    mapping = assets.surface_mapping
+    assert mapping is not None
+    samples = FlowSamples(
+        rows=np.asarray([1, 1], dtype=np.int32),
+        cols=np.asarray([1, 2], dtype=np.int32),
+        dx=np.asarray([0.8, 0.0]),
+        dy=np.asarray([0.0, 0.0]),
+        magnitude=np.asarray([1.6, 0.0]),
+        active=np.asarray([True, False]),
+    )
+    arrows, diags = build_flow_overlay(samples, mapping)
+    assert not diags
+    assert int(np.count_nonzero(arrows.lengths > 0.0)) == 1
+    assert int(np.count_nonzero(arrows.lengths < 0.0)) == 1
+    idle = arrows.colors[arrows.lengths < 0.0][0]
+    # Brand idle tint #8A93A6, not a ramp colour.
+    assert idle[0] == pytest.approx(0x8A / 255.0, abs=0.02)
+    assert idle[2] == pytest.approx(0xA6 / 255.0, abs=0.02)
+    positions, _triangles, colors = arrow_instances_to_mesh(arrows)
+    assert positions.shape[0] == colors.shape[0] > 0
+
+
 def test_missing_contact_yields_no_arrow() -> None:
     assets = poc_scene()
     mapping = assets.surface_mapping