diff --git a/VideoReceiverSFP/core/config.py b/VideoReceiverSFP/core/config.py
index 7a4e7b8..8ff9492 100644
--- a/VideoReceiverSFP/core/config.py
+++ b/VideoReceiverSFP/core/config.py
@@ -18,7 +18,11 @@ SAVE_RAW_UNKNOWN = True
 # Flags to also save decoded previews for quick inspection
 # MFD: save BMP; SAR/UNKNOWN: save BMP by default for lossless grayscale
 SAVE_BMP_MFD = False
-SAVE_BMP_SAR = True
+# By default do not automatically save decoded SAR previews; leave saving
+# under user control via the UI checkboxes. Previously this was True and
+# caused SAR previews to be written even when the user only enabled video
+# recording. Set to False to avoid unexpected saves.
+SAVE_BMP_SAR = False
 SAVE_BMP_UNKNOWN = True
 
 # Video recording defaults
diff --git a/VideoReceiverSFP/core/dump_manager.py b/VideoReceiverSFP/core/dump_manager.py
index 696b528..e69d9c4 100644
--- a/VideoReceiverSFP/core/dump_manager.py
+++ b/VideoReceiverSFP/core/dump_manager.py
@@ -172,13 +172,12 @@ class DumpManager:
             except Exception:
                 logger.exception("Error closing video writer")
             finally:
+                # Remove the active writer and runtime timestamp but keep
+                # the recorded video's start time/path so the UI can show
+                # the last produced file even after recording stopped.
                 self._video_writers.pop(category, None)
-                self._video_start_times.pop(category, None)
+                # keep _video_start_times[category] and _video_paths[category]
                 self._last_frame_timestamps.pop(category, None)
-                try:
-                    self._video_paths.pop(category, None)
-                except Exception:
-                    pass
 
     def _enqueue(self, path: str, category: str) -> None:
         """Track saved file and trigger pruning."""
diff --git a/VideoReceiverSFP/core/payload_dispatcher.py b/VideoReceiverSFP/core/payload_dispatcher.py
index 05772e5..ca7c636 100644
--- a/VideoReceiverSFP/core/payload_dispatcher.py
+++ b/VideoReceiverSFP/core/payload_dispatcher.py
@@ -168,19 +168,27 @@ def dispatch_frame(module: Any, frame: Any, leader: Optional[Any]) -> None:
                 pass
 
         # generic callbacks and saving
+        try:
+            is_mfd = (image_type_id == getattr(module, 'IMAGE_TYPE_MFD', 1))
+        except Exception:
+            is_mfd = False
+
         for cb in list(getattr(module, '_callbacks', [])):
             try:
-                if getattr(module, '_save_png', False) and Image is not None and hasattr(frame, 'save'):
+                # Only the MFD generic save is controlled by _save_png. SAR has its
+                # own _sar_save_png flag handled earlier. Save MFD previews under
+                # the 'mfd' category so get_last_saved_mfd() can find them.
+                if is_mfd and getattr(module, '_save_png', False) and Image is not None and hasattr(frame, 'save'):
                     try:
                         if getattr(module, '_dump_manager', None) is not None:
-                            saved = module._dump_manager.save_preview_from_pil(frame, category='frame', fmt='png')
+                            saved = module._dump_manager.save_preview_from_pil(frame, category='mfd', fmt='png')
                             if saved:
-                                logging.getLogger().info("VideoReceiverSFP: saved frame to %s", saved)
+                                logging.getLogger().info("VideoReceiverSFP: saved MFD preview to %s", saved)
                         else:
                             ts = time.strftime('%Y%m%d_%H%M%S') + (f"_{int(time.time() * 1000) % 1000:03d}")
                             dumps_dir = getattr(module, '_dumps_dir', os.path.join(os.getcwd(), 'dumps'))
                             os.makedirs(dumps_dir, exist_ok=True)
-                            pngpath = os.path.join(dumps_dir, f'VideoReceiverSFP_frame_{ts}.png')
+                            pngpath = os.path.join(dumps_dir, f'VideoReceiverSFP_mfd_{ts}.png')
                             frame.save(pngpath)
                             module._saved_pngs.append(pngpath)
                             while len(module._saved_pngs) > module._dump_keep:
@@ -190,7 +198,7 @@ def dispatch_frame(module: Any, frame: Any, leader: Optional[Any]) -> None:
                                 except Exception:
                                     pass
                     except Exception:
-                        logging.getLogger().exception('VideoReceiverSFP: failed to save preview png')
+                        logging.getLogger().exception('VideoReceiverSFP: failed to save MFD preview png')
                 try:
                     cb(frame)
                 except Exception:
diff --git a/VideoReceiverSFP/core/test_orchestrator.py b/VideoReceiverSFP/core/test_orchestrator.py
index 552e78d..066be8d 100644
--- a/VideoReceiverSFP/core/test_orchestrator.py
+++ b/VideoReceiverSFP/core/test_orchestrator.py
@@ -12,6 +12,7 @@ import logging
 import threading
 import tkinter as tk
 from tkinter import ttk
+from tkinter import messagebox
 
 from .sfp_module import SfpConnectorModule
 
@@ -326,8 +327,12 @@ def run_orchestrator():
                 rec_mfd = bool(mfd_vid_save_var.get())
                 rec_sar = bool(sar_vid_save_var.get())
 
-                # If nothing selected, do nothing (per user request)
+                # If nothing selected, inform the user and abort
                 if not (save_mfd or save_sar or rec_mfd or rec_sar):
+                    try:
+                        messagebox.showwarning("No selection", "Please select at least one save or record option before starting.")
+                    except Exception:
+                        pass
                     return
 
                 # Apply selections to module: image saving and video recording only while 'recording'