diff --git a/ofm_config_full.json b/ofm_config_full.json
index 6d4686ec..19b9e89a 100644
--- a/ofm_config_full.json
+++ b/ofm_config_full.json
@@ -16,6 +16,7 @@
                 "scans_folder": "/var/openflexure/scans/"
             }
         },
+        "histo_scan_workflow": "openflexure_microscope_server.things.scan_workflows:HistoScanWorkflow",
         "stage_measure": "openflexure_microscope_server.things.stage_measure:RangeofMotionThing",
         "bg_color_channels_luv": "openflexure_microscope_server.things.background_detect:ColourChannelDetectLUV",
         "bg_channel_deviations_luv": "openflexure_microscope_server.things.background_detect:ChannelDeviationLUV"
diff --git a/ofm_config_simulation.json b/ofm_config_simulation.json
index ef886fb4..8cc7602f 100644
--- a/ofm_config_simulation.json
+++ b/ofm_config_simulation.json
@@ -11,6 +11,7 @@
                 "scans_folder": "./openflexure/scans/"
             }
         },
+        "histo_scan_workflow": "openflexure_microscope_server.things.scan_workflows:HistoScanWorkflow",
         "bg_color_channels_luv": "openflexure_microscope_server.things.background_detect:ColourChannelDetectLUV",
         "bg_channel_deviations_luv": "openflexure_microscope_server.things.background_detect:ChannelDeviationLUV"
     },
diff --git a/src/openflexure_microscope_server/scan_directories.py b/src/openflexure_microscope_server/scan_directories.py
index 54a52dcc..86ab0455 100644
--- a/src/openflexure_microscope_server/scan_directories.py
+++ b/src/openflexure_microscope_server/scan_directories.py
@@ -8,12 +8,11 @@ import shutil
 import threading
 import zipfile
 from datetime import datetime, timedelta
-from typing import Annotated, Any, Mapping, Optional, Self
+from typing import Any, Mapping, Optional, Self
 
 from pydantic import (
     BaseModel,
     ConfigDict,
-    PlainSerializer,
     ValidationError,
     field_serializer,
     field_validator,
@@ -60,56 +59,20 @@ class StitchingData(BaseModel):
     """The overlap between adjacent images as a fraction of the image size."""
 
 
-def _coerce_lecacy_scan_data(data: dict) -> dict:
-    """Coerce any scan data from before version 2 into the version 2 format."""
-    # Before the current version no schema_version was set
-    if "schema_version" in data:
-        return data
+class BaseScanData(BaseModel):
+    """Data about a scan not including workflow specific data.
 
-    if "correlation_resize" and "overlap" in data:
-        correlation_resize = data.pop("correlation_resize")
-        # Note we don't pop overlap is a setting for the legacy workflow as well
-        # as a stitching setting.
-        # This is done because in future workflows the stitching overlap may be a
-        # directly set setting or something that is calculated from other settings.
-        overlap = data["overlap"]
-        data["stitching_settings"] = StitchingData(
-            correlation_resize=correlation_resize,
-            overlap=overlap,
-        )
-    else:
-        data["stitching_settings"] = None
+    For including workflow specific data see also:
 
-    # Add any legacy workflow settings that are found
-    legacy_keys = [
-        "overlap",
-        "max_dist",
-        "dx",
-        "dy",
-        "autofocus_dz",
-        "autofocus_on",
-        "skip_background",
-    ]
-    workflow_settings = {}
-    for key in legacy_keys:
-        if key in data:
-            workflow_settings[key] = data.pop(key)
+    * ActiveScanData which subclasses this including the BaseModel used by the
+        ScanWorkflow
+    * HistoricScanData which has the workflow specific data loaded as a dictionary.
 
-    data["workflow"] = "Legacy"
-    data["workflow_settings"] = workflow_settings
-    return data
-
-
-# This is a dictionary of a PyDantic model. It allows ScanData to hold arbitrary
-# workflow settings models during a scan.
-AnyModelOrDict = Annotated[
-    dict | BaseModel,
-    PlainSerializer(lambda v: v.model_dump(), return_type=dict),
-]
-
-
-class ScanData(BaseModel):
-    """Data about a scan to be saved to a JSON file in the directory.
+    Sepearating historic and active data allows workflows to use any BaseModel for its
+    settings, but for the data to be reloaded even if that model has updated or is not
+    available. Historic scan data loaded from disk is used for stitching and for
+    creating a ScanInfo object for  communicating with the UI. These uses are clearly
+    typed by this model.
 
     This serialises into a human readable format where possible with
 
@@ -153,31 +116,14 @@ class ScanData(BaseModel):
     This should be set with ``set_final_data()`` to ensure duration is set.
     """
 
-    workflow: str
-    """The class name of the workflow Thing."""
-
-    workflow_settings: AnyModelOrDict
-    """The settings for this workflow."""
-
     stitching_settings: Optional[StitchingData]
     """The data needed to stitch a scan.
 
     Set to None for types of scan that cannot be stitched.
     """
 
-    def set_final_data(self, result: str) -> None:
-        """Set the final data for the scan, scan duration is automatically calculated.
-
-        :param result: A string describing the result.
-        """
-        self.duration = datetime.now() - self.start_time
-        self.scan_result = result
-
-    @model_validator(mode="before")
-    @classmethod
-    def coerce_legacy(cls, data: dict) -> dict:
-        """Coerce any legacy data."""
-        return _coerce_lecacy_scan_data(data)
+    workflow: str
+    """The class name of the workflow Thing."""
 
     @model_validator(mode="after")
     def validate_schema_version(self) -> Self:
@@ -238,6 +184,53 @@ class ScanData(BaseModel):
         return "Unknown" if value is None else value
 
 
+class HistoricScanData(BaseScanData):
+    workflow_settings: dict
+    """A dictionary of the settings for the workflow that was used workflow."""
+
+    @model_validator(mode="before")
+    @classmethod
+    def coerce_legacy(cls, data: dict) -> dict:
+        """Coerce any legacy data."""
+        r"""Coerce any scan data from before version 2 into the version 2 format."""
+        # Before the current version no schema_version was set
+        if "schema_version" in data:
+            return data
+
+        if "correlation_resize" and "overlap" in data:
+            correlation_resize = data.pop("correlation_resize")
+            # Note we don't pop overlap is a setting for the legacy workflow as well
+            # as a stitching setting.
+            # This is done because in future workflows the stitching overlap may be a
+            # directly set setting or something that is calculated from other settings.
+            overlap = data["overlap"]
+            data["stitching_settings"] = StitchingData(
+                correlation_resize=correlation_resize,
+                overlap=overlap,
+            )
+        else:
+            data["stitching_settings"] = None
+
+        # Add any legacy workflow settings that are found
+        legacy_keys = [
+            "overlap",
+            "max_dist",
+            "dx",
+            "dy",
+            "autofocus_dz",
+            "autofocus_on",
+            "skip_background",
+        ]
+        workflow_settings = {}
+        for key in legacy_keys:
+            if key in data:
+                workflow_settings[key] = data.pop(key)
+
+        data["workflow"] = "Legacy"
+        data["workflow_settings"] = workflow_settings
+        return data
+
+
 class ScanDirectoryManager:
     """A class for managing interactions with scan directories."""
 
@@ -565,10 +558,10 @@ class ScanDirectory:
         except (json.decoder.JSONDecodeError, IOError):
             return None
 
-    def get_scan_data(self) -> Optional[ScanData]:
-        """Return the scan data from the json file as a ScanData model.
+    def get_scan_data(self) -> Optional[HistoricScanData]:
+        """Return the scan data from the json file as a HistoricScanData model.
 
-        :return: The data as a ScanData model or None if it couldn't be loaded or
+        :return: The data as a HistoricScanData model or None if it couldn't be loaded or
             valdiated.
         """
         data_dict = self.get_scan_data_dict()
@@ -576,7 +569,7 @@ class ScanDirectory:
             LOGGER.warning(f"Could not load scan data for {self.name}.")
             return None
         try:
-            return ScanData(**data_dict)
+            return HistoricScanData(**data_dict)
         except ValidationError:
             LOGGER.warning(f"Could not validate scan data for {self.name}.")
             return None
@@ -627,7 +620,7 @@ class ScanDirectory:
                 files.append(os.path.relpath(full_path, self.dir_path))
         return files
 
-    def save_scan_data(self, scan_data: ScanData) -> None:
+    def save_scan_data(self, scan_data: BaseScanData) -> None:
         """Save the scan data for this scan to disk."""
         if self.scan_data_path is None:
             raise FileNotFoundError(
diff --git a/src/openflexure_microscope_server/stitching.py b/src/openflexure_microscope_server/stitching.py
index e505971f..88e06df6 100644
--- a/src/openflexure_microscope_server/stitching.py
+++ b/src/openflexure_microscope_server/stitching.py
@@ -218,9 +218,11 @@ class FinalStitcher(BaseStitcher):
             if not known enter None. A value will be chosen from the scan_data_dict, or
             set to a default value if no value is available in the scan_data.
         :param stitch_tiff: Whether to stitch a pyramidal TIFF.
-        :param scan_data_dict: The ScanData for this scan as a dictionary. This is used
-            to read/calculate overlap and correlation_resize if they are not provided.
+        :param scan_data_dict: The HistoricScanData for this scan as a dictionary. This
+            is used to read/calculate overlap and correlation_resize if they are not
+            provided.
         """
+        # TODO ^fix the above historic data
         self.logger = logger
         overlap, correlation_resize = self._process_inputs(
             overlap=overlap,
diff --git a/src/openflexure_microscope_server/things/scan_workflows.py b/src/openflexure_microscope_server/things/scan_workflows.py
index d06ba985..feb81653 100644
--- a/src/openflexure_microscope_server/things/scan_workflows.py
+++ b/src/openflexure_microscope_server/things/scan_workflows.py
@@ -1,4 +1,11 @@
-from typing import Mapping, Optional
+from __future__ import annotations
+
+from typing import (
+    Generic,
+    Mapping,
+    Optional,
+    TypeVar,
+)
 
 from pydantic import BaseModel
 
@@ -16,16 +23,21 @@ from openflexure_microscope_server.things.autofocus import (
 from openflexure_microscope_server.things.background_detect import (
     ChannelDeviationLUV,
 )
+from openflexure_microscope_server.things.camera import BaseCamera
 from openflexure_microscope_server.things.camera_stage_mapping import CameraStageMapper
 
+SettingModelType = TypeVar("SettingModelType", bound=BaseModel)
 
-class ScanWorkflow(lt.Thing):
+
+class ScanWorkflow(Generic[SettingModelType], lt.Thing):
     """A base class for all Scanworkflows.
 
     Scan workflows set the behaviour of a scan, inclduing the background detection,
     scan planning, aquisition routine.
     """
 
+    _settings_model: type[SettingModelType]
+
     # All workdlows must have a set class for scan planning
     _planner_cls: type[ScanPlanner]
 
@@ -50,11 +62,13 @@ class ScanWorkflow(lt.Thing):
             "Each specific ScanWorkflow must implement a ready property."
         )
 
-    # TODO should be a model
-    def all_settings(self, images_dir: str) -> tuple[dict, Optional[StitchingData]]:
+    def all_settings(
+        self, images_dir: str
+    ) -> tuple[SettingModelType, Optional[StitchingData]]:
         """Return the scan settings and the stitching settings.
 
-        - The specific settings for this scan workflow are returned as a dict.
+        - The specific settings for this scan workflow are returned as a Base Model of
+            the type set when defining the class.
         - Stitiching settings are returned either as a StitchingData object or None
             is returned if it is not possible to stitch the scan.
         """
@@ -62,18 +76,20 @@ class ScanWorkflow(lt.Thing):
             "Each specific ScanWorkflow must implement a `all_settings`. method."
         )
 
-    def pre_scan_routine(self, settings: dict) -> None:
+    def pre_scan_routine(self, settings: SettingModelType) -> None:
         raise NotImplementedError(
             "Each specific ScanWorkflow must implement a pre-scan routine."
         )
 
-    def new_scan_planner(self, settings: dict, position: Mapping[str, int]) -> None:
+    def new_scan_planner(
+        self, settings: SettingModelType, position: Mapping[str, int]
+    ) -> ScanPlanner:
         raise NotImplementedError(
             "Each specific ScanWorkflow must implement a ``new_scan_planner`` method."
         )
 
     def aquisition_routine(
-        self, settings: dict, xyz_pos: tuple[int, int, int]
+        self, settings: SettingModelType, xyz_pos: tuple[int, int, int]
     ) -> tuple[bool, Optional[int]]:
         raise NotImplementedError(
             "Each specific ScanWorkflow must implement an aquisition routine"
@@ -83,8 +99,8 @@ class ScanWorkflow(lt.Thing):
 class HistoScanSettingsModel(BaseModel):
     """The settings including needed for running a HistoScan.
 
-    This includes settings caluclated when starting. This will be serialised in
-    ScanData.
+    This includes settings caluclated when starting. This will be held by smart scan
+    during a scan and serialised to disk.
     """
 
     overlap: float
@@ -92,14 +108,16 @@ class HistoScanSettingsModel(BaseModel):
     dx: int
     dy: int
     skip_background: bool
-    smart_stack_prarams: SmartStackParams
+    smart_stack_params: SmartStackParams
 
 
-class HistoScanWorkflow(ScanWorkflow):
+class HistoScanWorkflow(ScanWorkflow[HistoScanSettingsModel]):
+    _settings_model = HistoScanSettingsModel
+    _planner_cls: type[ScanPlanner] = SmartSpiral
     # Thing Slots
     _background_detector: ChannelDeviationLUV = lt.thing_slot()
+    _cam: BaseCamera = lt.thing_slot()
     _csm: CameraStageMapper = lt.thing_slot()
-    _planner_cls: type[ScanPlanner] = SmartSpiral
     _autofocus: AutofocusThing = lt.thing_slot()
 
     # Scan settings
@@ -147,7 +165,8 @@ class HistoScanWorkflow(ScanWorkflow):
     * 200 for 20x
     """
 
-    # noqa, scan_name is unused but is needed for equivalence with other workflows.
+    # The noqa statment is because scan_name is unused but is needed for equivalence
+    # with other workflows that may want to validate the scan name.
     def check_before_start(self, scan_name: str) -> None:  # noqa: ARG002
         """Before starting a scan, check that background and camera-stage-mapping are set.
 
@@ -191,12 +210,13 @@ class HistoScanWorkflow(ScanWorkflow):
             correlation_resize=STITCHING_RESOLUTION[0] / self.save_resolution[0],
         )
 
-        dx, dy = self._calc_displacement_from_test_image(self.overlap)
+        dx, dy = self._calc_displacement_from_overlap(self.overlap)
         self.logger.info(
             f"Based on an overlap of {self.overlap}, the stage will make steps of "
             f"{dx}, {dy}"
         )
 
+        # TODO: set a min on the property
         autofocus_dz = self.autofocus_dz
         if autofocus_dz == 0:
             self.logger.info("Running scan without autofocus")
@@ -207,7 +227,7 @@ class HistoScanWorkflow(ScanWorkflow):
             )
             autofocus_dz = 0
 
-        smart_stack_prarams = self.create_smart_stack_params(
+        smart_stack_params = self.create_smart_stack_params(
             images_dir=images_dir,
             autofocus_dz=autofocus_dz,
             save_resolution=self.save_resolution,
@@ -219,9 +239,8 @@ class HistoScanWorkflow(ScanWorkflow):
             dx=dx,
             dy=dy,
             skip_background=self.skip_background,
-            smart_stack_prarams=smart_stack_prarams,
+            smart_stack_params=smart_stack_params,
         )
-        autofocus_dz = (autofocus_dz,)
 
         return scan_settings, stitching_settings
 
@@ -233,7 +252,9 @@ class HistoScanWorkflow(ScanWorkflow):
 
         :returns: (dx, dy) - the x and y displacements in steps
         """
-        csm_image_res = [int(i) for i in self._csm.image_resolution]
+        csm_image_res = self._csm.image_resolution
+        if csm_image_res is None:
+            raise RuntimeError("CSM not set. Scan shouldn't have progresses this far.")
 
         # Calculate displacements in image coordinates
         dx_img = csm_image_res[1] * (1 - overlap)
@@ -320,11 +341,13 @@ class HistoScanWorkflow(ScanWorkflow):
         )
 
     def pre_scan_routine(self, settings: HistoScanSettingsModel) -> None:
-        self._autofocus.looping_autofocus(dz=settings.autofocus_dz, start="centre")
+        self._autofocus.looping_autofocus(
+            dz=settings.smart_stack_params.autofocus_dz, start="centre"
+        )
 
     def new_scan_planner(
         self, settings: HistoScanSettingsModel, position: Mapping[str, int]
-    ) -> None:
+    ) -> ScanPlanner:
         # The initial plan for the scan should be a single x,y position. All future
         # moves will be planned around this point. In future, route planner could
         # have multiple starting positions, each of which will be visited before the
@@ -349,7 +372,11 @@ class HistoScanWorkflow(ScanWorkflow):
         """
         # If skipping background, take an image to check if current field of view is background
         if settings.skip_background:
-            capture_image, bg_message = self._cam.image_is_sample()
+            image_array = self._cam.grab_as_array(stream_name="lores")
+            capture_image, bg_message = self._background_detector.image_is_sample(
+                image_array
+            )
+            del image_array
 
         if not capture_image:
             msg = f"Skipping {xyz_pos} as it is {bg_message}."
@@ -358,7 +385,8 @@ class HistoScanWorkflow(ScanWorkflow):
 
         save_on_failure = settings.skip_background
 
-        focused, focused_height = self._autofocus.run_smart_stack(
+        focus_height: Optional[int]
+        focused, focus_height = self._autofocus.run_smart_stack(
             stack_parameters=settings.smart_stack_params,
             save_on_failure=save_on_failure,
         )
@@ -368,6 +396,6 @@ class HistoScanWorkflow(ScanWorkflow):
         # run_smart_stage always returns a focus height for the sharpest image even
         # if it failed to find a good focus. Set to None if not focussed.
         if not focused:
-            focused_height = None
+            focus_height = None
 
-        return imaged, focused_height
+        return imaged, focus_height
diff --git a/src/openflexure_microscope_server/things/smart_scan.py b/src/openflexure_microscope_server/things/smart_scan.py
index 4207783a..97a56e36 100644
--- a/src/openflexure_microscope_server/things/smart_scan.py
+++ b/src/openflexure_microscope_server/things/smart_scan.py
@@ -13,6 +13,7 @@ import time
 from datetime import datetime
 from subprocess import SubprocessError
 from typing import (
+    Annotated,
     Any,
     Callable,
     Concatenate,
@@ -24,16 +25,14 @@ from typing import (
 
 from fastapi import HTTPException
 from fastapi.responses import FileResponse
-from pydantic import BaseModel
+from pydantic import BaseModel, PlainSerializer
 
 import labthings_fastapi as lt
 
 from openflexure_microscope_server import scan_directories, stitching
 
 # Things
-from .autofocus import AutofocusThing, StackParams
 from .camera import BaseCamera
-from .camera_stage_mapping import CameraStageMapper
 from .scan_workflows import HistoScanWorkflow, ScanWorkflow
 from .stage import BaseStage
 
@@ -41,6 +40,26 @@ T = TypeVar("T")
 P = ParamSpec("P")
 
 
+# This  allows ActiveScanData to hold arbitrary workflow settings models during a scan.
+AnyModel = Annotated[
+    BaseModel,
+    PlainSerializer(lambda value: value.model_dump(), return_type=dict),
+]
+
+
+class ActiveScanData(scan_directories.BaseScanData):
+    workflow_settings: AnyModel
+    """The settings for the ongoing workflow."""
+
+    def set_final_data(self, result: str) -> None:
+        """Set the final data for the scan, scan duration is automatically calculated.
+
+        :param result: A string describing the result.
+        """
+        self.duration = datetime.now() - self.start_time
+        self.scan_result = result
+
+
 class ScanListInfo(BaseModel):
     """The information to be sent to the Scan List tab."""
 
@@ -99,9 +118,7 @@ class SmartScanThing(lt.Thing):
     past scans.
     """
 
-    _autofocus: AutofocusThing = lt.thing_slot()
     _cam: BaseCamera = lt.thing_slot()
-    _csm: CameraStageMapper = lt.thing_slot()
     _stage: BaseStage = lt.thing_slot()
     _workflow: HistoScanWorkflow = lt.thing_slot()
 
@@ -118,19 +135,6 @@ class SmartScanThing(lt.Thing):
         self._scan_dir_manager = scan_directories.ScanDirectoryManager(scans_folder)
         self._scan_lock = threading.Lock()
 
-    # Variables set by the scan
-    _stack_params: Optional[StackParams] = None
-
-    @property
-    def stack_params(self) -> StackParams:
-        """The parameters for z-stacking during the onging scan.
-
-        Only read this property is a scan is ongoing or it will raise an error.
-        """
-        if self._stack_params is None:
-            raise RuntimeError("Cannot get stack parameters as they are not set.")
-        return self._stack_params
-
     _ongoing_scan: Optional[scan_directories.ScanDirectory] = None
 
     @property
@@ -143,11 +147,11 @@ class SmartScanThing(lt.Thing):
             raise ScanNotRunningError("Cannot get ongoing scan if scan is not running.")
         return self._ongoing_scan
 
-    _scan_data: Optional[scan_directories.ScanData] = None
+    _scan_data: Optional[ActiveScanData] = None
 
     @property
-    def scan_data(self) -> scan_directories.ScanData:
-        """The ScanData object jolding information about the of the ongoing scan.
+    def scan_data(self) -> ActiveScanData:
+        """The ActiveScanData object holding information about the of the ongoing scan.
 
         Only read this property is a scan is ongoing or it will raise an error.
         """
@@ -157,18 +161,6 @@ class SmartScanThing(lt.Thing):
 
     _preview_stitcher: Optional[stitching.PreviewStitcher] = None
 
-    @property
-    def preview_stitcher(self) -> stitching.PreviewStitcher:
-        """The PreviewStitcher object for stitching live previews.
-
-        Only read this property is a scan is ongoing or it will raise an error.
-        """
-        if self._preview_stitcher is None:
-            raise ScanNotRunningError(
-                "No preview stitcher agailable as scan is not running."
-            )
-        return self._preview_stitcher
-
     _latest_scan_name: Optional[str] = None
 
     @lt.property
@@ -218,7 +210,6 @@ class SmartScanThing(lt.Thing):
             self._scan_lock.release()
             # Ensure any PreviewStitcher created cannot be reused.
             self._preview_stitcher = None
-            self._stack_params = None
 
         # Remove any scan folders containing zero images.
         self.purge_empty_scans()
@@ -248,7 +239,7 @@ class SmartScanThing(lt.Thing):
         return (next_point[0], next_point[1], z_estimate)
 
     @_scan_running
-    def _collect_scan_data(self, workflow: ScanWorkflow) -> scan_directories.ScanData:
+    def _collect_scan_data(self, workflow: ScanWorkflow) -> ActiveScanData:
         """Collect and return the data for this scan so it cannot be changed mid-scan."""
         # Record starting position so it can be returned to at end of scan.
         starting_position = self._stage.position
@@ -266,7 +257,7 @@ class SmartScanThing(lt.Thing):
         auto_stitch = self.stitch_automatically and stitching_settings is not None
 
         # Fix scan parameters in case UI is updated during scan.
-        return scan_directories.ScanData(
+        return ActiveScanData(
             scan_name=self.ongoing_scan.name,
             starting_position=starting_position,
             start_time=datetime.now(),
@@ -290,13 +281,13 @@ class SmartScanThing(lt.Thing):
     @_scan_running
     def _manage_stitching_threads(self) -> None:
         """Manage the stitching threads, starting them if needed and not already running."""
-        if self.scan_data.stitching_settings is None:
+        if self._preview_stitcher is None:
             # This scan can't stitch.
             return
         # Assume 4 images means at least one offset in x and y, making the stitching
         # well constrained.
-        if self.scan_data.image_count > 3 and not self.preview_stitcher.running:
-            self.preview_stitcher.start()
+        if self.scan_data.image_count > 3 and not self._preview_stitcher.running:
+            self._preview_stitcher.start()
 
     @_scan_running
     def _run_scan(self, workflow: ScanWorkflow) -> None:
@@ -309,7 +300,8 @@ class SmartScanThing(lt.Thing):
         try:
             self._cam.start_streaming(main_resolution=(3280, 2464))
             self._scan_data = self._collect_scan_data(workflow)
-            workflow.pre_scan_routine(self._scan_data)
+
+            workflow.pre_scan_routine(self._scan_data.workflow_settings)
             self.ongoing_scan.save_scan_data(self._scan_data)
             images_dir = self.ongoing_scan.images_dir
             # Type narrowing
@@ -317,11 +309,16 @@ class SmartScanThing(lt.Thing):
                 raise RuntimeError(
                     "Couldn't run scan, images directory was not created."
                 )
-            self._preview_stitcher = stitching.PreviewStitcher(
-                images_dir,
-                overlap=self.scan_data.overlap,
-                correlation_resize=self.scan_data.correlation_resize,
-            )
+
+            # If stitching settings are None then this type of scan can't be stitched
+            if self.scan_data.stitching_settings is not None:
+                # Settings exist, so create preview stitcher
+                stitching_settings = self.scan_data.stitching_settings
+                self._preview_stitcher = stitching.PreviewStitcher(
+                    images_dir,
+                    overlap=stitching_settings.overlap,
+                    correlation_resize=stitching_settings.correlation_resize,
+                )
 
             # This is the main loop of the scan!
             self._main_scan_loop(workflow)
@@ -386,6 +383,7 @@ class SmartScanThing(lt.Thing):
             if focus_height is None:
                 focused = False
             else:
+                focused = True
                 current_pos_xyz = (new_pos_xyz[0], new_pos_xyz[1], focus_height)
 
             route_planner.mark_location_visited(
@@ -426,17 +424,18 @@ class SmartScanThing(lt.Thing):
 
         self.logger.info("Waiting for background processes to finish...")
 
-        # Actually check the sticher exists rather than using self.preview_sticher as
+        # Check the sticher exists rather than using self.preview_sticher as
         # this method can be called during exception handling.
         if self._preview_stitcher is not None:
             self._preview_stitcher.wait()
 
-        if self.scan_data.stitch_automatically:
+        stitching_settings = self.scan_data.stitching_settings
+        if self.scan_data.stitch_automatically and stitching_settings is not None:
             self.logger.info("Stitching final image (may take some time)...")
             self.stitch_scan(
                 scan_name=self.ongoing_scan.name,
-                correlation_resize=self.scan_data.correlation_resize,
-                overlap=self.scan_data.overlap,
+                correlation_resize=stitching_settings.correlation_resize,
+                overlap=stitching_settings.overlap,
             )
 
     @lt.endpoint(