diff --git a/openflexure_microscope/api/app.py b/openflexure_microscope/api/app.py
index 3e8a8209..e3cce530 100644
--- a/openflexure_microscope/api/app.py
+++ b/openflexure_microscope/api/app.py
@@ -1,5 +1,6 @@
 #!/usr/bin/env python
 from gevent import monkey
+
 monkey.patch_all()
 
 import time
diff --git a/openflexure_microscope/api/default_extensions/__init__.py b/openflexure_microscope/api/default_extensions/__init__.py
index e90646d7..87ad694d 100644
--- a/openflexure_microscope/api/default_extensions/__init__.py
+++ b/openflexure_microscope/api/default_extensions/__init__.py
@@ -2,6 +2,7 @@ import logging
 import traceback
 from contextlib import contextmanager
 
+
 @contextmanager
 def handle_extension_error(extension_name):
     """'gracefully' log an error if an extension fails to load."""
@@ -12,6 +13,7 @@ def handle_extension_error(extension_name):
             f"Exception loading builtin extension picamera_autocalibrate: \n{traceback.format_exc()}"
         )
 
+
 with handle_extension_error("autofocus"):
     from .autofocus import autofocus_extension_v2
 with handle_extension_error("scan"):
diff --git a/openflexure_microscope/api/default_extensions/autofocus.py b/openflexure_microscope/api/default_extensions/autofocus.py
index fc9f4a0a..97ea2e45 100644
--- a/openflexure_microscope/api/default_extensions/autofocus.py
+++ b/openflexure_microscope/api/default_extensions/autofocus.py
@@ -51,7 +51,9 @@ class JPEGSharpnessMonitor:
     def start(self):
         "Start monitoring sharpness by looking at JPEG size"
         if not self.camera.stream_active:
-            logging.warn("Autofocus sharpness monitor was started but the camera isn't streaming.  Attempting to start the stream...")
+            logging.warn(
+                "Autofocus sharpness monitor was started but the camera isn't streaming.  Attempting to start the stream..."
+            )
             self.camera.start_stream_recording()
         self.background_thread = Thread(target=self._measure_jpegs)
         self.background_thread.start()
@@ -106,7 +108,9 @@ class JPEGSharpnessMonitor:
             stop = np.argmax(jpeg_times > stage_times[1])
         except ValueError as e:
             if np.sum(jpeg_times > stage_times[0]) == 0:
-                raise ValueError("No images were captured during the move of the stage.  Perhaps the camera is not streaming images?")
+                raise ValueError(
+                    "No images were captured during the move of the stage.  Perhaps the camera is not streaming images?"
+                )
             else:
                 raise e
         if stop < 1:
@@ -120,7 +124,9 @@ class JPEGSharpnessMonitor:
         """Return the z position of the sharpest image on a given move"""
         jt, jz, js = self.move_data(index)
         if len(js) == 0:
-            raise ValueError("No images were captured during the move of the stage.  Perhaps the camera is not streaming images?")
+            raise ValueError(
+                "No images were captured during the move of the stage.  Perhaps the camera is not streaming images?"
+            )
         return jz[np.argmax(js)]
 
     def data_dict(self):
@@ -212,7 +218,9 @@ def move_and_find_focus(microscope, dz):
 
 def fast_autofocus(microscope, dz=2000, backlash=None):
     """Perform a down-up-down-up autofocus"""
-    with monitor_sharpness(microscope) as m, microscope.camera.lock, microscope.stage.lock:
+    with monitor_sharpness(
+        microscope
+    ) as m, microscope.camera.lock, microscope.stage.lock:
         i, z = m.focus_rel(-dz / 2)
         i, z = m.focus_rel(dz)
         fz = m.sharpest_z_on_move(i)
@@ -262,7 +270,9 @@ def fast_up_down_up_autofocus(
             might slightly hurt accuracy, but is unlikely to be a big issue.  Too big
             may cause you to overshoot, which is a problem.
     """
-    with monitor_sharpness(microscope) as m, microscope.camera.lock, microscope.stage.lock:
+    with monitor_sharpness(
+        microscope
+    ) as m, microscope.camera.lock, microscope.stage.lock:
         # Ensure the MJPEG stream has started
         microscope.camera.start_stream_recording()
 
@@ -372,7 +382,9 @@ class FastAutofocusAPI(View):
 
         if microscope.has_real_stage():
             logging.debug("Running autofocus...")
-            task = taskify(fast_up_down_up_autofocus)(microscope, dz=dz, mini_backlash=backlash)
+            task = taskify(fast_up_down_up_autofocus)(
+                microscope, dz=dz, mini_backlash=backlash
+            )
 
             # return a handle on the autofocus task
             return task
@@ -382,12 +394,15 @@ class FastAutofocusAPI(View):
 
 
 autofocus_extension_v2 = BaseExtension(
-    "org.openflexure.autofocus", version="2.0.0",
-    description="Actions to move the microscope in Z and pick the point with the sharpest image."
+    "org.openflexure.autofocus",
+    version="2.0.0",
+    description="Actions to move the microscope in Z and pick the point with the sharpest image.",
 )
 
 autofocus_extension_v2.add_method(fast_autofocus, "fast_autofocus")
-autofocus_extension_v2.add_method(fast_up_down_up_autofocus, "fast_up_down_up_autofocus")
+autofocus_extension_v2.add_method(
+    fast_up_down_up_autofocus, "fast_up_down_up_autofocus"
+)
 autofocus_extension_v2.add_method(autofocus, "autofocus")
 
 autofocus_extension_v2.add_view(MeasureSharpnessAPI, "/measure_sharpness")
diff --git a/openflexure_microscope/api/default_extensions/camera_stage_mapping/array_with_attrs.py b/openflexure_microscope/api/default_extensions/camera_stage_mapping/array_with_attrs.py
index 61fe164a..db99d630 100644
--- a/openflexure_microscope/api/default_extensions/camera_stage_mapping/array_with_attrs.py
+++ b/openflexure_microscope/api/default_extensions/camera_stage_mapping/array_with_attrs.py
@@ -7,13 +7,14 @@ Created on Tue May 26 08:08:14 2015
 
 import numpy as np
 
+
 class AttributeDict(dict):
     """This class extends a dictionary to have a "create" method for
     compatibility with h5py attrs objects."""
-    
+
     def create(self, name, data):
         self[name] = data
-        
+
     def modify(self, name, data):
         self[name] = data
 
@@ -22,7 +23,8 @@ class AttributeDict(dict):
         for k in list(self.keys()):
             if isinstance(self[k], np.ndarray):
                 self[k] = np.copy(self[k])
-        
+
+
 def ensure_attribute_dict(obj, copy=False):
     """Given a mapping that may or not be an AttributeDict, return an
     AttributeDict object that either is, or copies the data of, the input."""
@@ -33,15 +35,17 @@ def ensure_attribute_dict(obj, copy=False):
         if copy:
             out.copy_arrays()
         return out
-        
+
+
 def ensure_attrs(obj):
     """Return an ArrayWithAttrs version of an array-like object, may be the
     original object if it already has attrs."""
-    if hasattr(obj, 'attrs'):
-        return obj #if it has attrs, do nothing
+    if hasattr(obj, "attrs"):
+        return obj  # if it has attrs, do nothing
     else:
-        return ArrayWithAttrs(obj) #otherwise, wrap it
-        
+        return ArrayWithAttrs(obj)  # otherwise, wrap it
+
+
 class ArrayWithAttrs(np.ndarray):
     """A numpy ndarray, with an AttributeDict accessible as array.attrs.
     
@@ -50,7 +54,7 @@ class ArrayWithAttrs(np.ndarray):
     a lot to the ``InfoArray`` example in `numpy` documentation on subclassing
     `numpy.ndarray`.
     """
-    
+
     def __new__(cls, input_array, attrs={}):
         """Make a new ndarray, based on an existing one, with an attrs dict.
         
@@ -64,26 +68,29 @@ class ArrayWithAttrs(np.ndarray):
         obj.attrs = ensure_attribute_dict(attrs)
         # return the new object
         return obj
-        
+
     def __array_finalize__(self, obj):
         # this is called by numpy when the object is created (__new__ may or
         # may not get called)
-        if obj is None: return # if obj is None, __new__ was called - do nothing
+        if obj is None:
+            return  # if obj is None, __new__ was called - do nothing
         # if we didn't create the object with __new__,  we must add the attrs
         # dictionary.  We copy this from the source object if possible (while
         # ensuring it's the right type) or create a new, empty one if not.
         # NB we don't use ensure_attribute_dict because we want to make sure the
         # dict object is *copied* not merely referenced.
-        self.attrs = ensure_attribute_dict(getattr(obj, 'attrs', {}), copy=True)
+        self.attrs = ensure_attribute_dict(getattr(obj, "attrs", {}), copy=True)
+
 
 def attribute_bundler(attrs):
     """Return a function that bundles the supplied attributes with an array."""
+
     def bundle_attrs(array):
         return ArrayWithAttrs(array, attrs=attrs)
 
 
 class DummyHDF5Group(dict):
-    def __init__(self,dictionary, attrs ={}, name="DummyHDF5Group"):
+    def __init__(self, dictionary, attrs={}, name="DummyHDF5Group"):
         super(DummyHDF5Group, self).__init__()
         self.attrs = attrs
         for key in dictionary:
@@ -92,4 +99,4 @@ class DummyHDF5Group(dict):
         self.basename = name
 
     file = None
-    parent = None
\ No newline at end of file
+    parent = None
diff --git a/openflexure_microscope/api/default_extensions/camera_stage_mapping/camera_stage_calibration_1d.py b/openflexure_microscope/api/default_extensions/camera_stage_mapping/camera_stage_calibration_1d.py
index 12554440..84636afc 100644
--- a/openflexure_microscope/api/default_extensions/camera_stage_mapping/camera_stage_calibration_1d.py
+++ b/openflexure_microscope/api/default_extensions/camera_stage_mapping/camera_stage_calibration_1d.py
@@ -12,9 +12,11 @@ from numpy.linalg import norm
 from .camera_stage_tracker import Tracker, move_until_motion_detected
 import logging
 
+
 def displacements(positions):
     """Calculate the absolute distance of each point from the first point."""
-    return norm(positions - positions[0,:][np.newaxis,:], axis=1)
+    return norm(positions - positions[0, :][np.newaxis, :], axis=1)
+
 
 def direction_from_points(points):
     """Given an Nx2 array of points, figure out the principal component.
@@ -25,7 +27,8 @@ def direction_from_points(points):
     points = points.astype(np.float)
     points -= np.mean(points, axis=0)[np.newaxis, :]
     eigenvalues, eigenvectors = np.linalg.eig(np.cov(points.T))
-    return eigenvectors[:,np.argmax(eigenvalues)]
+    return eigenvectors[:, np.argmax(eigenvalues)]
+
 
 def apply_backlash(x, backlash=0, start_unwound=True):
     """Apply a basic model of backlash to a set of coordinates.
@@ -42,14 +45,15 @@ def apply_backlash(x, backlash=0, start_unwound=True):
         y[0] = x[0] + initial_direction * backlash
     else:
         y[0] = x[0]
-    for i in range(1,len(x)):
-        d = x[i] - y[i-1]
+    for i in range(1, len(x)):
+        d = x[i] - y[i - 1]
         if np.abs(d) >= backlash:
             y[i] = x[i] - np.sign(d) * backlash
         else:
-            y[i] = y[i-1]
+            y[i] = y[i - 1]
     return y
 
+
 def fit_backlash(moves):
     """Given a set of linear moves forwards and back, estimate backlash.
 
@@ -99,7 +103,7 @@ def fit_backlash(moves):
         residuals = yfit - (xfit_blsh * m + c)
         return m, c, np.std(residuals, ddof=3)
 
-    max_backlash = (np.max(xfit) - np.min(xfit))/3
+    max_backlash = (np.max(xfit) - np.min(xfit)) / 3
     backlash_values = []
     residual_values = []
     backlash = 0
@@ -107,18 +111,18 @@ def fit_backlash(moves):
         m, c, residual = fit_motion(xfit, yfit, backlash)
         residual_values.append(residual)
         backlash_values.append(backlash)
-        backlash += max(1, backlash/3)
+        backlash += max(1, backlash / 3)
 
     backlash = backlash_values[np.argmin(residual_values)]
     m, c, residual = fit_motion(xfit, yfit, backlash)
 
-    fractional_error = residual/norm(np.diff(yfit))
+    fractional_error = residual / norm(np.diff(yfit))
     if fractional_error > 0.1:
         raise ValueError("The fit didn't look successful")
 
     return {
-        "backlash": backlash, 
-        "pixels_per_step": m, 
+        "backlash": backlash,
+        "pixels_per_step": m,
         "fractional_error": fractional_error,
         "stage_direction": stage_direction,
         "image_direction": image_direction,
@@ -126,36 +130,42 @@ def fit_backlash(moves):
     }
 
 
-def calibrate_backlash_1d(tracker, move, direction=np.array([1,0,0])):
+def calibrate_backlash_1d(tracker, move, direction=np.array([1, 0, 0])):
     """Figure out reasonable step sizes for calibration, and estimate the backlash."""
-    try: # Ensure that the tracker has a template set
+    try:  # Ensure that the tracker has a template set
         _ = tracker.template
     except:
         tracker.acquire_template()
     assert tracker.stage_positions.shape[0] == 1
-    original_stage_pos = tracker.stage_positions[-1,:]
+    original_stage_pos = tracker.stage_positions[-1, :]
 
-    direction = direction / np.sum(direction**2)**0.5 # ensure "direction" is normalised
+    direction = (
+        direction / np.sum(direction ** 2) ** 0.5
+    )  # ensure "direction" is normalised
 
     logging.info("Moving the stage until we see motion...")
     # Move the stage until we can see a significant amount of motion
     i, m = move_until_motion_detected(
-        tracker, move, direction, threshold=tracker.max_safe_displacement * 0.2)
-    
+        tracker, move, direction, threshold=tracker.max_safe_displacement * 0.2
+    )
+
     logging.info("Moving the stage to the edge of the field of view...")
     i, m = move_until_motion_detected(
-        tracker, move, direction, 
+        tracker,
+        move,
+        direction,
         threshold=tracker.max_safe_displacement * 0.7,
-        multipliers=m/2.0 * np.arange(20),
-        detect_cumulative_motion=True)
+        multipliers=m / 2.0 * np.arange(20),
+        detect_cumulative_motion=True,
+    )
     exponential_moves = tracker.history
 
     # Include this final step, and make a rough estimate of the scaling from stage to image
     stage_pos, image_pos = tracker.history
     stage_step = stage_pos[-1, :] - stage_pos[-1 - i, :]
     image_step = image_pos[-1, :] - image_pos[-1 - i, :]
-    steps_per_pixel = norm(stage_step)/norm(image_step)
-    
+    steps_per_pixel = norm(stage_step) / norm(image_step)
+
     # Calculate a step that moves roughly 0.2 times the max. displacement (i.e. 0.1 times the FoV)
     sensible_step = direction * tracker.max_safe_displacement * 0.2 * steps_per_pixel
     tracker.reset_history()
@@ -167,27 +177,35 @@ def calibrate_backlash_1d(tracker, move, direction=np.array([1,0,0])):
     starting_stage_pos, starting_camera_pos = tracker.append_point()
     for i in range(15):
         move(starting_stage_pos - sensible_step * (i + 1))
-        #print(".", end="")
+        # print(".", end="")
         stage_pos, image_pos = tracker.append_point()
-        if (i > 3 and tracker.moving_away_from_centre 
-            and norm(image_pos) > 0.65 * tracker.max_safe_displacement):
-            break # Stop once we have moved far enough
+        if (
+            i > 3
+            and tracker.moving_away_from_centre
+            and norm(image_pos) > 0.65 * tracker.max_safe_displacement
+        ):
+            break  # Stop once we have moved far enough
 
     logging.info("Moving the stage forwards to measure backlash (2/2)")
     # Move forwards again, in 10 steps
     starting_stage_pos, starting_camera_pos = tracker.append_point()
     for i in range(15):
         move(starting_stage_pos + sensible_step * (i + 1))
-        #print(".", end="")
+        # print(".", end="")
         stage_pos, image_pos = tracker.append_point()
-        if (i > 3 and tracker.moving_away_from_centre 
-            and norm(image_pos) > 0.65 * tracker.max_safe_displacement):
-            break # Stop once we have moved far enough
+        if (
+            i > 3
+            and tracker.moving_away_from_centre
+            and norm(image_pos) > 0.65 * tracker.max_safe_displacement
+        ):
+            break  # Stop once we have moved far enough
     linear_moves = tracker.history
 
     try:
         res = fit_backlash(linear_moves)
-        backlash_correction = sensible_step / norm(sensible_step) * res["backlash"] * 1.5
+        backlash_correction = (
+            sensible_step / norm(sensible_step) * res["backlash"] * 1.5
+        )
 
         # Finally, move back to the starting position, doing backlash-corrected moves.
         logging.info("Moving back to the start, correcting for backlash...")
@@ -200,32 +218,39 @@ def calibrate_backlash_1d(tracker, move, direction=np.array([1,0,0])):
         backlash_corrected_moves = tracker.history
         move(original_stage_pos - backlash_correction)
     except ValueError:
-        return {"exponential_moves": exponential_moves, "linear_moves": linear_moves,}
+        return {"exponential_moves": exponential_moves, "linear_moves": linear_moves}
     finally:
         # Reset position
         move(original_stage_pos)
 
     logging.info(f"Estimated backlash {res['backlash']:.0f} steps")
-    logging.info(f"Stage-to-image ratio {np.abs(res['pixels_per_step']):.3f} pixels/step")
-    logging.info(f"Residuals were about {res['fractional_error']:.2f} times the step size")
+    logging.info(
+        f"Stage-to-image ratio {np.abs(res['pixels_per_step']):.3f} pixels/step"
+    )
+    logging.info(
+        f"Residuals were about {res['fractional_error']:.2f} times the step size"
+    )
 
-    res.update({
-        "exponential_moves": exponential_moves,
-        "linear_moves": linear_moves,
-        "backlash_corrected_moves": backlash_corrected_moves
-    })
+    res.update(
+        {
+            "exponential_moves": exponential_moves,
+            "linear_moves": linear_moves,
+            "backlash_corrected_moves": backlash_corrected_moves,
+        }
+    )
     return res
 
 
 def plot_1d_backlash_calibration(results):
     """Plot the results of a calibration run"""
     from matplotlib import pyplot as plt
-    f, ax = plt.subplots(1,2)
-    
+
+    f, ax = plt.subplots(1, 2)
+
     for k in ["exponential", "linear", "backlash_corrected"]:
-        moves = results[k+"_moves"]
+        moves = results[k + "_moves"]
         if moves is not None:
-            ax[0].plot(moves[1][:,0], moves[1][:,1], 'o-')
+            ax[0].plot(moves[1][:, 0], moves[1][:, 1], "o-")
     ax[0].set_aspect(1, adjustable="datalim")
 
     image_direction = results["image_direction"]
@@ -237,19 +262,20 @@ def plot_1d_backlash_calibration(results):
         image_1d = np.sum(image_pos * image_direction[np.newaxis, :], axis=1)
         return stage_1d, image_1d
 
-    ax[1].plot(*convert_moves(results["exponential_moves"]), 'o-')
-    
+    ax[1].plot(*convert_moves(results["exponential_moves"]), "o-")
+
     stage_pos, image_pos = convert_moves(results["linear_moves"])
     model = apply_backlash(stage_pos, results["backlash"])
     model *= results["pixels_per_step"]
     model += np.mean(image_pos) - np.mean(model)
-    ax[1].plot(stage_pos, model, '-')
-    ax[1].plot(stage_pos, image_pos, 'o')
+    ax[1].plot(stage_pos, model, "-")
+    ax[1].plot(stage_pos, image_pos, "o")
     if results["backlash_corrected_moves"] is not None:
-        ax[1].plot(*convert_moves(results["backlash_corrected_moves"]), '+')
+        ax[1].plot(*convert_moves(results["backlash_corrected_moves"]), "+")
 
     return f, ax
 
+
 def image_to_stage_displacement_from_1d(calibrations):
     """Combine X and Y calibrations
 
@@ -271,9 +297,11 @@ def image_to_stage_displacement_from_1d(calibrations):
         c_blash = np.abs(cal["backlash"] * cal["stage_direction"])
         backlash[backlash < c_blash] = c_blash[backlash < c_blash]
 
-    A, res, rank, s = np.linalg.lstsq(image_vectors, stage_vectors) # we solve image*A = stage
+    A, res, rank, s = np.linalg.lstsq(
+        image_vectors, stage_vectors
+    )  # we solve image*A = stage
     return {
         "image_to_stage_displacement": A,
         "backlash_vector": backlash,
         "backlash": np.max(backlash),
-    }
\ No newline at end of file
+    }
diff --git a/openflexure_microscope/api/default_extensions/camera_stage_mapping/camera_stage_tracker.py b/openflexure_microscope/api/default_extensions/camera_stage_mapping/camera_stage_tracker.py
index 9c7a7235..a065216b 100644
--- a/openflexure_microscope/api/default_extensions/camera_stage_mapping/camera_stage_tracker.py
+++ b/openflexure_microscope/api/default_extensions/camera_stage_mapping/camera_stage_tracker.py
@@ -12,10 +12,11 @@ from numpy.linalg import norm
 import cv2
 from scipy import ndimage
 
+
 def central_half(image):
     """Return the central 50% (in X and Y) of an image"""
     w, h = image.shape[:2]
-    return image[int(w/4):int(3*w/4),int(h/4):int(3*h/4), ...]
+    return image[int(w / 4) : int(3 * w / 4), int(h / 4) : int(3 * h / 4), ...]
 
 
 def datum_pixel(image):
@@ -23,7 +24,8 @@ def datum_pixel(image):
     try:
         return np.array(image.datum_pixel)
     except:
-        return (np.array(image.shape[:2]) - 1) / 2.
+        return (np.array(image.shape[:2]) - 1) / 2.0
+
 
 def locate_feature_in_image(image, feature, margin=0, restrict=False):
     """Find the given feature (small image) and return the position of its datum (or centre) in the image's pixels.
@@ -47,31 +49,51 @@ def locate_feature_in_image(image, feature, margin=0, restrict=False):
     image to yield the position in the sample of the feature you're looking for.
     """
     # The line below is superfluous if we keep the datum-aware code below it.
-    assert image.shape[0] > feature.shape[0] and image.shape[1] > feature.shape[1], "Image must be larger than feature!"
+    assert (
+        image.shape[0] > feature.shape[0] and image.shape[1] > feature.shape[1]
+    ), "Image must be larger than feature!"
     # Check that there's enough space around the feature image
     lower_margin = datum_pixel(image) - datum_pixel(feature)
-    upper_margin = (image.shape[:2] - datum_pixel(image)) - (feature.shape[:2] - datum_pixel(feature))
-    assert np.all(np.array([lower_margin, upper_margin]) >= margin), "The feature image is too large."
-    #TODO: sensible auto-crop of the template if it's too large?
-    image_shift = np.array((0,0))
+    upper_margin = (image.shape[:2] - datum_pixel(image)) - (
+        feature.shape[:2] - datum_pixel(feature)
+    )
+    assert np.all(
+        np.array([lower_margin, upper_margin]) >= margin
+    ), "The feature image is too large."
+    # TODO: sensible auto-crop of the template if it's too large?
+    image_shift = np.array((0, 0))
     if restrict:
         # if requested, crop the larger image so that our search area is (2*margin + 1) square.
-        image_shift = np.array(lower_margin - margin,dtype = int)
-        image = image[image_shift[0]:image_shift[0] + feature.shape[0] + 2 * margin + 1,
-                      image_shift[1]:image_shift[1] + feature.shape[1] + 2 * margin + 1, ...]
+        image_shift = np.array(lower_margin - margin, dtype=int)
+        image = image[
+            image_shift[0] : image_shift[0] + feature.shape[0] + 2 * margin + 1,
+            image_shift[1] : image_shift[1] + feature.shape[1] + 2 * margin + 1,
+            ...,
+        ]
 
-    corr = cv2.matchTemplate(image, feature,
-                             cv2.TM_SQDIFF_NORMED)  # correlate them: NB the match position is the MINIMUM
-    corr = -corr # invert the image so we can find a peak
-    corr += (corr.max() - corr.min()) * 0.1 - corr.max()  # background-subtract 90% of maximum
+    corr = cv2.matchTemplate(
+        image, feature, cv2.TM_SQDIFF_NORMED
+    )  # correlate them: NB the match position is the MINIMUM
+    corr = -corr  # invert the image so we can find a peak
+    corr += (
+        corr.max() - corr.min()
+    ) * 0.1 - corr.max()  # background-subtract 90% of maximum
     corr = cv2.threshold(corr, 0, 0, cv2.THRESH_TOZERO)[
-        1]  # zero out any negative pixels - but there should always be > 0 nonzero pixels
-    assert np.sum(corr) > 0, "Error: the correlation image doesn't have any nonzero pixels."
-    peak = ndimage.measurements.center_of_mass(corr)  # take the centroid (NB this is of grayscale values, not binary)
-    pos = np.array(peak) + image_shift + datum_pixel(feature) # return the position of the feature's datum point.
+        1
+    ]  # zero out any negative pixels - but there should always be > 0 nonzero pixels
+    assert (
+        np.sum(corr) > 0
+    ), "Error: the correlation image doesn't have any nonzero pixels."
+    peak = ndimage.measurements.center_of_mass(
+        corr
+    )  # take the centroid (NB this is of grayscale values, not binary)
+    pos = (
+        np.array(peak) + image_shift + datum_pixel(feature)
+    )  # return the position of the feature's datum point.
     return pos
 
-class Tracker():
+
+class Tracker:
     def __init__(self, grab_image, get_position, settle=None):
         """A class to manage moving the stage and following motion in the image
         
@@ -98,11 +120,11 @@ class Tracker():
         self.margin = np.array([0, 0])
         self._template_position = np.array([0.0, 0.0])
         self.image_shape = None
-    
+
     def get_position(self):
         """Get the position of the stage"""
         return np.array(self._get_position())
-    
+
     def settle(self):
         """Wait a short time and discard an image so the stage is no longer wobbling."""
         if self._settle is not None:
@@ -110,7 +132,7 @@ class Tracker():
         else:
             time.sleep(0.3)
             self._grab_image()
-            
+
     @property
     def template(self):
         """The template image (should be a numpy array)"""
@@ -118,12 +140,14 @@ class Tracker():
             raise ValueError("Attempt to use the tracker before setting the template")
         else:
             return self._template
-        
+
     @template.setter
     def template(self, new_value):
         self._template = new_value
-        
-    def acquire_template(self, settle=True, reset_history=True, relative_positions=True):
+
+    def acquire_template(
+        self, settle=True, reset_history=True, relative_positions=True
+    ):
         """Take a new image, and use it as the template.  NB this records the initial point.
         
         We will wait for the stage to settle, then acquire a new image to use as the template.
@@ -151,26 +175,32 @@ class Tracker():
         self.margin = np.array(image.shape)[:2] - np.array(self.template.shape)[:2]
         if reset_history:
             self.reset_history()
-        self._template_position = np.array([0., 0.])
+        self._template_position = np.array([0.0, 0.0])
         if relative_positions:
-            self._template_position = self.track_image(image) # Position should be zero initially
+            self._template_position = self.track_image(
+                image
+            )  # Position should be zero initially
         self.append_point(settle=False)
-        
+
     @property
     def max_displacement(self):
         """The highest position values that can be tracked"""
-        return self.margin // 2 # TODO: be cleverer about non-trivial values of template_position
-    
+        return (
+            self.margin // 2
+        )  # TODO: be cleverer about non-trivial values of template_position
+
     @property
     def min_displacement(self):
         """The lowest position values that can be tracked"""
-        return -self.max_displacement # TODO: be cleverer about non-trivial template_position values
-    
+        return (
+            -self.max_displacement
+        )  # TODO: be cleverer about non-trivial template_position values
+
     @property
     def max_safe_displacement(self):
         """The biggest displacement we can safely attempt to track without knowing direction."""
         return np.min(np.concatenate([self.max_displacement, -self.min_displacement]))
-            
+
     def track_image(self, image):
         """Find the position of the image relative to the template
         
@@ -182,8 +212,8 @@ class Tracker():
         a minus sign in front of `locate_feature_in_image` in the source
         code.
         """
-        return - locate_feature_in_image(image, self.template) - self._template_position
-    
+        return -locate_feature_in_image(image, self.template) - self._template_position
+
     def append_point(self, settle=True, image=None):
         """Find the current position using both stage and image, and append it"""
         if settle:
@@ -195,22 +225,22 @@ class Tracker():
         self._image_positions.append(image_pos)
         self._stage_positions.append(stage_pos)
         return stage_pos, image_pos
-        
+
     @property
     def stage_positions(self):
         """An array of positions we have moved the stage to"""
         return np.array(self._stage_positions)
-    
+
     @property
     def image_positions(self):
         """An array of positions we have moved the stage to"""
         return np.array(self._image_positions)
-    
+
     @property
     def history(self):
         """Return arrays of stage, image positions"""
         return self.stage_positions, self.image_positions
-    
+
     def reset_history(self, leave_first_point=False):
         """Reset the positions and displacements recorded"""
         if leave_first_point:
@@ -232,10 +262,17 @@ class Tracker():
         if len(self.image_positions) < 2:
             return None
         else:
-            return norm(self.image_positions[-1,:]) > norm(self.image_positions[-2])
-    
-   
-def move_until_motion_detected(tracker, move, displacement, threshold=10, multipliers=2**np.arange(16), detect_cumulative_motion=False):
+            return norm(self.image_positions[-1, :]) > norm(self.image_positions[-2])
+
+
+def move_until_motion_detected(
+    tracker,
+    move,
+    displacement,
+    threshold=10,
+    multipliers=2 ** np.arange(16),
+    detect_cumulative_motion=False,
+):
     """Move the stage until we can detect motion in the camera.
     
     We move the stage in the direction given by ``displacement`` until the 
@@ -259,14 +296,21 @@ def move_until_motion_detected(tracker, move, displacement, threshold=10, multip
     `displacement * m`.
     """
     displacement = np.array(displacement)
-    starting_image_position = tracker.image_positions[0 if detect_cumulative_motion else -1, :]
+    starting_image_position = tracker.image_positions[
+        0 if detect_cumulative_motion else -1, :
+    ]
     starting_stage_position = tracker.stage_positions[-1, :]
     for i, m in enumerate(multipliers):
         move(starting_stage_position + displacement * m)
         tracker.append_point()
         if norm(tracker.image_positions[-1, :] - starting_image_position) >= threshold:
             return i + 1, m
-    raise Exception("Moved the stage by {} but saw no motion.".format(multipliers[-1] * displacement))
+    raise Exception(
+        "Moved the stage by {} but saw no motion.".format(
+            multipliers[-1] * displacement
+        )
+    )
+
 
 def concatenate_tracker_histories(histories):
     """Combine a number of separate tracker history entries into one
@@ -286,4 +330,3 @@ def concatenate_tracker_histories(histories):
     """
     components = zip(*histories)
     return tuple(np.concatenate(c, axis=1) for c in components)
-    
\ No newline at end of file
diff --git a/openflexure_microscope/api/default_extensions/camera_stage_mapping/extension.py b/openflexure_microscope/api/default_extensions/camera_stage_mapping/extension.py
index 50648237..cbb02235 100644
--- a/openflexure_microscope/api/default_extensions/camera_stage_mapping/extension.py
+++ b/openflexure_microscope/api/default_extensions/camera_stage_mapping/extension.py
@@ -6,7 +6,12 @@ This file contains the HTTP API for camera/stage calibration.
 from labthings.server.view import View
 from labthings.server.find import find_component
 from labthings.server.extensions import BaseExtension
-from labthings.server.decorators import marshal_task, ThingAction, use_args, ThingProperty
+from labthings.server.decorators import (
+    marshal_task,
+    ThingAction,
+    use_args,
+    ThingProperty,
+)
 from labthings.server import fields
 
 from labthings.core.tasks import taskify
@@ -23,7 +28,10 @@ import io
 import os
 import json
 
-from .camera_stage_calibration_1d import calibrate_backlash_1d, image_to_stage_displacement_from_1d
+from .camera_stage_calibration_1d import (
+    calibrate_backlash_1d,
+    image_to_stage_displacement_from_1d,
+)
 from .camera_stage_tracker import Tracker
 
 from openflexure_microscope.utilities import axes_to_array
@@ -33,15 +41,15 @@ from openflexure_microscope.config import JSONEncoder
 CSM_DATAFILE_NAME = "csm_calibration.json"
 CSM_DATAFILE_PATH = data_file_path(CSM_DATAFILE_NAME)
 
+
 class CSMExtension(BaseExtension):
     """
     Use the camera as an encoder, so we can relate camera and stage coordinates
     """
+
     def __init__(self):
         BaseExtension.__init__(
-            self,
-            "org.openflexure.camera_stage_mapping",
-            version="0.0.1",
+            self, "org.openflexure.camera_stage_mapping", version="0.0.1"
         )
 
     _microscope = None
@@ -52,10 +60,10 @@ class CSMExtension(BaseExtension):
         if self._microscope is None:
             self._microscope = find_component("org.openflexure.microscope")
         return self._microscope
-    
+
     def update_settings(self, settings):
         """Update the stored extension settings dictionary"""
-        keys = ["extensions",self.name]
+        keys = ["extensions", self.name]
         dictionary = create_from_path(keys)
         set_by_path(dictionary, keys, settings)
         logging.info(f"Updating settings with {dictionary}")
@@ -64,20 +72,20 @@ class CSMExtension(BaseExtension):
 
     def get_settings(self):
         """Retrieve the settings for this extension"""
-        keys = ["extensions",self.name]
+        keys = ["extensions", self.name]
         return get_by_path(self.microscope.read_settings(), keys)
 
     def camera_stage_functions(self):
         """Return functions that allow us to interface with the microscope"""
-        self.microscope.camera.start_worker() # ensure the worker thread is running, so there is an MJPEG stream
-        
+        self.microscope.camera.start_worker()  # ensure the worker thread is running, so there is an MJPEG stream
+
         def grab_image():
             jpeg = self.microscope.camera.get_frame()
             return np.array(PIL.Image.open(io.BytesIO(jpeg)))
-        
+
         def get_position():
             return self.microscope.stage.position
-        
+
         move = self.microscope.stage.move_abs
 
         return grab_image, get_position, move
@@ -96,10 +104,10 @@ class CSMExtension(BaseExtension):
     def calibrate_xy(self):
         """Move the microscope's stage in X and Y, to calibrate its relationship to the camera"""
         logging.info("Calibrating X axis:")
-        cal_x = self.calibrate_1d(np.array([1,0,0]))
+        cal_x = self.calibrate_1d(np.array([1, 0, 0]))
         logging.info("Calibrating Y axis:")
-        cal_y = self.calibrate_1d(np.array([0,1,0]))
-        
+        cal_y = self.calibrate_1d(np.array([0, 1, 0]))
+
         # Combine X and Y calibrations to make a 2D calibration
         cal_xy = image_to_stage_displacement_from_1d([cal_x, cal_y])
         self.update_settings(cal_xy)
@@ -110,7 +118,7 @@ class CSMExtension(BaseExtension):
             "linear_calibration_y": cal_y,
         }
 
-        with open(CSM_DATAFILE_PATH, 'w') as f:
+        with open(CSM_DATAFILE_PATH, "w") as f:
             json.dump(data, f, cls=JSONEncoder)
 
         return data
@@ -130,27 +138,28 @@ class CSMExtension(BaseExtension):
         self.microscope.stage.move_rel([relative_move[0], relative_move[1], 0])
 
 
-
-
 csm_extension = CSMExtension()
 
+
 @ThingAction
 class Calibrate1DView(View):
-    @use_args({
-        "direction": fields.List(fields.Float(), required=True, example=[1,0,0])
-    })
+    @use_args(
+        {"direction": fields.List(fields.Float(), required=True, example=[1, 0, 0])}
+    )
     @marshal_task
     def post(self, args):
         """Calibrate one axis of the microscope stage against the camera."""
-        
+
         direction = np.array(args.get("direction"))
 
         task = taskify(csm_extension.calibrate_1d)(direction)
 
         return task
 
+
 csm_extension.add_view(Calibrate1DView, "/calibrate_1d")
 
+
 @ThingAction
 class CalibrateXYView(View):
     @marshal_task
@@ -160,24 +169,39 @@ class CalibrateXYView(View):
 
         return task
 
+
 csm_extension.add_view(CalibrateXYView, "/calibrate_xy")
 
 
 @ThingAction
 class MoveInImageCoordinatesView(View):
-    @use_args({
-        "x": fields.Float(description="The number of pixels to move in X", required=True, example=100),
-        "y": fields.Float(description="The number of pixels to move in Y", required=True, example=100),
-    })
+    @use_args(
+        {
+            "x": fields.Float(
+                description="The number of pixels to move in X",
+                required=True,
+                example=100,
+            ),
+            "y": fields.Float(
+                description="The number of pixels to move in Y",
+                required=True,
+                example=100,
+            ),
+        }
+    )
     def post(self, args):
         logging.debug("moving in pixels")
         """Move the microscope stage, such that we move by a given number of pixels on the camera"""
-        csm_extension.move_in_image_coordinates(np.array([args.get("x"), args.get("y")]))
-        
+        csm_extension.move_in_image_coordinates(
+            np.array([args.get("x"), args.get("y")])
+        )
+
         return csm_extension.microscope.state["stage"]["position"]
 
+
 csm_extension.add_view(MoveInImageCoordinatesView, "/move_in_image_coordinates")
 
+
 @ThingProperty
 class GetCalibrationFile(View):
     def get(self):
@@ -186,9 +210,10 @@ class GetCalibrationFile(View):
         datafile_path = CSM_DATAFILE_PATH
 
         if os.path.isfile(datafile_path):
-            with open(datafile_path, 'rb') as f:
+            with open(datafile_path, "rb") as f:
                 return json.load(f)
         else:
             return {}
 
-csm_extension.add_view(GetCalibrationFile, "/get_calibration")
\ No newline at end of file
+
+csm_extension.add_view(GetCalibrationFile, "/get_calibration")
diff --git a/openflexure_microscope/api/default_extensions/camera_stage_mapping/image_with_location.py b/openflexure_microscope/api/default_extensions/camera_stage_mapping/image_with_location.py
index baef69d6..a0063169 100644
--- a/openflexure_microscope/api/default_extensions/camera_stage_mapping/image_with_location.py
+++ b/openflexure_microscope/api/default_extensions/camera_stage_mapping/image_with_location.py
@@ -38,9 +38,11 @@ from past.utils import old_div
 import numpy as np
 from array_with_attrs import ArrayWithAttrs, ensure_attrs
 import cv2
-#import cv2.cv
+
+# import cv2.cv
 from scipy import ndimage
 
+
 class ImageWithLocation(ArrayWithAttrs):
     """An image, as a numpy array, with attributes to provide location information
     
@@ -49,9 +51,10 @@ class ImageWithLocation(ArrayWithAttrs):
     that we use to store the crucial mapping from pixels in the image to position in the
     sample.  
     """
-#    def __array_finalize__(self, obj):
-#        """Ensure that the object is a properly set-up ImageWithLocation"""
-#        ArrayWithAttrs.__array_finalize__(self, obj) # Ensure we have self.attrs
+
+    #    def __array_finalize__(self, obj):
+    #        """Ensure that the object is a properly set-up ImageWithLocation"""
+    #        ArrayWithAttrs.__array_finalize__(self, obj) # Ensure we have self.attrs
     def __getitem__(self, item):
         """Update the metadata when we extract a slice"""
         try:
@@ -61,18 +64,24 @@ class ImageWithLocation(ArrayWithAttrs):
             assert isinstance(item[0], slice), "First index was not a slice"
             assert isinstance(item[1], slice), "Second index was not a slice"
             start = np.array([item[i].start for i in range(2)])
-            start = np.where(start == np.array(None), 0, start) # missing start points are equivalent to zero
+            start = np.where(
+                start == np.array(None), 0, start
+            )  # missing start points are equivalent to zero
             step = np.array([item[i].step for i in range(2)])
-            step = np.where(step == np.array(None), 1, step) # missing step is equivalent to step==1
+            step = np.where(
+                step == np.array(None), 1, step
+            )  # missing step is equivalent to step==1
         except:
             # If the above doesn't work, assume we're not dealing with a 2D slice and give up.
-            return super(ImageWithLocation, self).__getitem__(item) # pass it on up
+            return super(ImageWithLocation, self).__getitem__(item)  # pass it on up
 
-        out = super(ImageWithLocation, self).__getitem__(item) # retrieve the slice
-        out.datum_pixel -= start # adjust the datum pixel so it refers to the same part of the image
+        out = super(ImageWithLocation, self).__getitem__(item)  # retrieve the slice
+        out.datum_pixel -= (
+            start
+        )  # adjust the datum pixel so it refers to the same part of the image
         # Next, we adjust the constant part of the pixel-sample matrix so pixels stay in the same place
-        location_shift = np.dot(ensure_3d(start), self.pixel_to_sample_matrix[:3,:3])
-        out.pixel_to_sample_matrix[3,:3] += location_shift
+        location_shift = np.dot(ensure_3d(start), self.pixel_to_sample_matrix[:3, :3])
+        out.pixel_to_sample_matrix[3, :3] += location_shift
         if not np.all(step == 1):
             # if we're downsampling, remember to scale datum_pixel accordingly
             out.datum_pixel = old_div(out.datum_pixel, step)
@@ -105,18 +114,22 @@ class ImageWithLocation(ArrayWithAttrs):
         A 2- or 3- element position, to match the size of location passed in.
         """
         l = ensure_2d(location)
-        l = l[:2]-self.pixel_to_sample_matrix[3,:2]
-        p = np.dot(l, np.linalg.inv(self.pixel_to_sample_matrix[:2,:2]))
+        l = l[:2] - self.pixel_to_sample_matrix[3, :2]
+        p = np.dot(l, np.linalg.inv(self.pixel_to_sample_matrix[:2, :2]))
         if check_bounds:
             assert np.all(0 <= p[0:2]), "The location was not within the image"
-            assert np.all(p[0:2] <= self.shape[0:2]), "The location was not within the image"
-            assert np.abs(p[2]) < z_tolerance, "The location was too far away from the plane of the image"
+            assert np.all(
+                p[0:2] <= self.shape[0:2]
+            ), "The location was not within the image"
+            assert (
+                np.abs(p[2]) < z_tolerance
+            ), "The location was too far away from the plane of the image"
         if len(location) == 2:
             return p[:2]
         else:
             return p[:3]
 
-    def feature_at(self, centre_position, size=(100,100), set_datum_to_centre=True):
+    def feature_at(self, centre_position, size=(100, 100), set_datum_to_centre=True):
         """Return a thumbnail cropped out of this image, centred on a particular pixel position.
 
         This is simply a convenience method that saves typing over the usual slice syntax.  Below are two equivalent
@@ -139,14 +152,25 @@ class ImageWithLocation(ArrayWithAttrs):
             float(size[0])
             float(size[1])
         except:
-            raise IndexError("Error: arguments of feature_at were invalid: {}, {}".format(centre_position, size))
+            raise IndexError(
+                "Error: arguments of feature_at were invalid: {}, {}".format(
+                    centre_position, size
+                )
+            )
         pos = centre_position
 
         # For now, rely on numpy to complain if the feature is outside the image.  May do bound-checking at some point.
         # If so, we might need to think carefully about the datum pixel of the resulting image.
-        thumb = self[pos[0] - old_div(size[0],2):pos[0] + old_div(size[0],2), pos[1] - old_div(size[1],2):pos[1] + old_div(size[1],2), ...]
+        thumb = self[
+            pos[0] - old_div(size[0], 2) : pos[0] + old_div(size[0], 2),
+            pos[1] - old_div(size[1], 2) : pos[1] + old_div(size[1], 2),
+            ...,
+        ]
         if set_datum_to_centre:
-            thumb.datum_pixel = (old_div(size[0],2), old_div(size[1],2)) # Make the datum point of the new image its centre.
+            thumb.datum_pixel = (
+                old_div(size[0], 2),
+                old_div(size[1], 2),
+            )  # Make the datum point of the new image its centre.
         return thumb
 
     def downsample(self, n):
@@ -156,7 +180,9 @@ class ImageWithLocation(ArrayWithAttrs):
         to noise.  Currently it just decimates (i.e. throws away rows and columns).
         """
         assert n > 0, "The downsampling factor must be an integer greater than 0"
-        return self[::int(n), ::int(n), ...] # The slicing code handles updating metadata
+        return self[
+            :: int(n), :: int(n), ...
+        ]  # The slicing code handles updating metadata
 
     @property
     def datum_pixel(self):
@@ -165,14 +191,16 @@ class ImageWithLocation(ArrayWithAttrs):
         Usually the datum pixel is the central pixel, and if the metadata required is not present,
         we will silently assume that this is the case.
         """
-        datum = self.attrs.get('datum_pixel', old_div((np.array(self.shape[:2]) - 1),2))
+        datum = self.attrs.get(
+            "datum_pixel", old_div((np.array(self.shape[:2]) - 1), 2)
+        )
         assert len(datum) == 2, "The datum pixel didn't have length 2!"
         return datum
 
     @datum_pixel.setter
     def datum_pixel(self, datum):
         assert len(datum) == 2, "The datum pixel didn't have length 2!"
-        self.attrs['datum_pixel'] = datum
+        self.attrs["datum_pixel"] = datum
 
     @property
     def datum_location(self):
@@ -186,34 +214,36 @@ class ImageWithLocation(ArrayWithAttrs):
         np.dot(p, M) yields a location for the given pixel, where p is [x,y,0,1] and M is this matrix.  The location
         given will be 4 elements long, and will have 1 as the final element.
         """
-        M = self.attrs['pixel_to_sample_matrix']
+        M = self.attrs["pixel_to_sample_matrix"]
         assert M.shape == (4, 4), "The pixel-to-sample matrix is the wrong shape!"
         assert M.dtype.kind == "f", "The pixel-to-sample matrix is not floating point!"
         return M
 
     @pixel_to_sample_matrix.setter
     def pixel_to_sample_matrix(self, M):
-        M = np.asanyarray(M) #ensure it's an ndarray subclass
+        M = np.asanyarray(M)  # ensure it's an ndarray subclass
         assert M.shape == (4, 4), "The pixel-to-sample matrix must be 4x4!"
         assert M.dtype.kind == "f", "The pixel-to-sample matrix must be floating point!"
-        self.attrs['pixel_to_sample_matrix'] = M
+        self.attrs["pixel_to_sample_matrix"] = M
+
+    # TODO: split the data type out of this module and put it somewhere sensible
 
-    #TODO: split the data type out of this module and put it somewhere sensible
 
 def add_location_metadata(image, pixel_to_sample_matrix, datum_pixel=None):
     """Wrap an image if needed, and set its pixel to sample matrix."""
-    awa = ensure_attrs(image) # if needed, convert the image to an ArrayWithAttrs
-    awa.attrs['pixel_to_sample_matrix'] = pixel_to_sample_matrix
+    awa = ensure_attrs(image)  # if needed, convert the image to an ArrayWithAttrs
+    awa.attrs["pixel_to_sample_matrix"] = pixel_to_sample_matrix
     if datum_pixel is not None:
-        awa.attrs['datum_pixel'] = datum_pixel
+        awa.attrs["datum_pixel"] = datum_pixel
     return awa
 
+
 def datum_pixel(image):
     """Get the datum pixel of an image - if no property is present, assume the central pixel."""
     try:
         return np.array(image.datum_pixel)
     except:
-        return (np.array(image.shape[:2]) - 1) / 2.
+        return (np.array(image.shape[:2]) - 1) / 2.0
 
 
 def ensure_3d(vector):
@@ -223,7 +253,9 @@ def ensure_3d(vector):
     elif len(vector) == 2:
         return np.array([vector[0], vector[1], 0])
     else:
-        raise ValueError("Tried to ensure a vector was 3D, but it had neither 2 nor 3 elements!")
+        raise ValueError(
+            "Tried to ensure a vector was 3D, but it had neither 2 nor 3 elements!"
+        )
 
 
 def ensure_2d(vector):
@@ -233,5 +265,6 @@ def ensure_2d(vector):
     elif len(vector) == 3:
         return np.array(vector[:2])
     else:
-        raise ValueError("Tried to ensure a vector was 2D, but it had neither 2 nor 3 elements!")
-
+        raise ValueError(
+            "Tried to ensure a vector was 2D, but it had neither 2 nor 3 elements!"
+        )
diff --git a/openflexure_microscope/api/default_extensions/picamera_autocalibrate/extension.py b/openflexure_microscope/api/default_extensions/picamera_autocalibrate/extension.py
index 8a22e7f8..ff48ed0b 100644
--- a/openflexure_microscope/api/default_extensions/picamera_autocalibrate/extension.py
+++ b/openflexure_microscope/api/default_extensions/picamera_autocalibrate/extension.py
@@ -13,7 +13,12 @@ import logging
 # Type hinting
 from typing import Tuple
 
-from .recalibrate_utils import recalibrate_camera, auto_expose_and_freeze_settings, flat_lens_shading_table
+from .recalibrate_utils import (
+    recalibrate_camera,
+    auto_expose_and_freeze_settings,
+    flat_lens_shading_table,
+)
+
 
 @contextmanager
 def pause_stream(scamera, resolution: Tuple[int, int] = None):
@@ -23,7 +28,9 @@ def pause_stream(scamera, resolution: Tuple[int, int] = None):
     block has finished.
     """
     with scamera.lock:
-        assert not scamera.record_active, "We can't pause the camera's video stream while a recording is in progress."
+        assert (
+            not scamera.record_active
+        ), "We can't pause the camera's video stream while a recording is in progress."
         streaming = scamera.stream_active
         old_resolution = scamera.camera.resolution
         if streaming:
@@ -37,6 +44,7 @@ def pause_stream(scamera, resolution: Tuple[int, int] = None):
                 logging.info("Restarting stream in pause_stream context manager")
                 scamera.start_stream_recording()
 
+
 def recalibrate(microscope):
     """Reset the camera's settings.
 
@@ -45,7 +53,9 @@ def recalibrate(microscope):
     with a gray level of 230.  It takes a little while to run.
     """
     with pause_stream(microscope.camera) as scamera:
-        auto_expose_and_freeze_settings(scamera.camera) # scamera.camera is the PiCamera object
+        auto_expose_and_freeze_settings(
+            scamera.camera
+        )  # scamera.camera is the PiCamera object
         recalibrate_camera(scamera.camera)
     microscope.save_settings()
 
@@ -63,13 +73,17 @@ class RecalibrateView(View):
 
         return taskify(recalibrate)(microscope)
 
+
 @ThingAction
 class FlattenLSTView(View):
     def post(self):
         microscope = find_component("org.openflexure.microscope")
 
         if not microscope:
-            abort(503, "No microscope connected. Unable to flatten the lens shading table.")
+            abort(
+                503,
+                "No microscope connected. Unable to flatten the lens shading table.",
+            )
 
         try:
             with pause_stream(microscope.camera) as scamera:
@@ -78,7 +92,11 @@ class FlattenLSTView(View):
             microscope.save_settings()
         except:
             logging.exception("Error flattening the lens shading table.")
-            abort(503, "Couldn't flatten the lens shading table - do you have the forked PiCamera library installed?")
+            abort(
+                503,
+                "Couldn't flatten the lens shading table - do you have the forked PiCamera library installed?",
+            )
+
 
 @ThingAction
 class DeleteLSTView(View):
@@ -86,7 +104,10 @@ class DeleteLSTView(View):
         microscope = find_component("org.openflexure.microscope")
 
         if not microscope:
-            abort(503, "No microscope connected. Unable to flatten the lens shading table.")
+            abort(
+                503,
+                "No microscope connected. Unable to flatten the lens shading table.",
+            )
 
         try:
             with pause_stream(microscope.camera) as scamera:
@@ -94,11 +115,16 @@ class DeleteLSTView(View):
             microscope.save_settings()
         except:
             logging.exception("Error deleting the lens shading table.")
-            abort(503, "Couldn't flatten the lens shading table - do you have the forked PiCamera library installed?")
+            abort(
+                503,
+                "Couldn't flatten the lens shading table - do you have the forked PiCamera library installed?",
+            )
 
 
 lst_extension_v2 = BaseExtension(
-    "org.openflexure.calibration.picamera", version="2.0.0-beta.1", description="Routines to perform flat-field correction on the camera."
+    "org.openflexure.calibration.picamera",
+    version="2.0.0-beta.1",
+    description="Routines to perform flat-field correction on the camera.",
 )
 
 lst_extension_v2.add_method(
diff --git a/openflexure_microscope/api/default_extensions/scan.py b/openflexure_microscope/api/default_extensions/scan.py
index ef788a05..30a0baa1 100644
--- a/openflexure_microscope/api/default_extensions/scan.py
+++ b/openflexure_microscope/api/default_extensions/scan.py
@@ -199,7 +199,7 @@ def tile(
                     # Run slow autofocus. Client should provide dz ~ 50
                     autofocus_extension.autofocus(
                         microscope,
-                        range(-3 * autofocus_dz, 4 * autofocus_dz, autofocus_dz)
+                        range(-3 * autofocus_dz, 4 * autofocus_dz, autofocus_dz),
                     )
                     logging.debug("Finished autofocus")
                     time.sleep(1)
diff --git a/openflexure_microscope/api/v2/views/actions/__init__.py b/openflexure_microscope/api/v2/views/actions/__init__.py
index 19bf25eb..e06454c5 100644
--- a/openflexure_microscope/api/v2/views/actions/__init__.py
+++ b/openflexure_microscope/api/v2/views/actions/__init__.py
@@ -58,7 +58,7 @@ def enabled_root_actions():
     return {k: v for k, v in _actions.items() if v["conditions"]}
 
 
-#@Tag("actions")
+# @Tag("actions")
 class ActionsView(View):
     def get(self):
         """
diff --git a/openflexure_microscope/config.py b/openflexure_microscope/config.py
index 6657de24..74ffb3f0 100644
--- a/openflexure_microscope/config.py
+++ b/openflexure_microscope/config.py
@@ -203,4 +203,3 @@ with open(DEFAULT_CONFIGURATION_FILE_PATH, "r") as default_configuration:
 user_configuration = OpenflexureSettingsFile(
     path=CONFIGURATION_FILE_PATH, defaults=DEFAULT_CONFIGURATION
 )
-
diff --git a/openflexure_microscope/microscope.py b/openflexure_microscope/microscope.py
index c36d4690..d8db1def 100644
--- a/openflexure_microscope/microscope.py
+++ b/openflexure_microscope/microscope.py
@@ -175,7 +175,12 @@ class Microscope:
         don't get removed from the settings file.
         """
 
-        settings_current = {"id": self.id, "name": self.name, "fov": self.fov, "extensions": self.extension_settings}
+        settings_current = {
+            "id": self.id,
+            "name": self.name,
+            "fov": self.fov,
+            "extensions": self.extension_settings,
+        }
 
         # If attached to a camera
         if self.camera:
diff --git a/openflexure_microscope/utilities.py b/openflexure_microscope/utilities.py
index 63db1651..185478f6 100644
--- a/openflexure_microscope/utilities.py
+++ b/openflexure_microscope/utilities.py
@@ -28,12 +28,7 @@ def ndarray_to_json(arr: np.ndarray):
         # This comes in very handy for the lens shading table.
         arr = np.array(arr)
     b64_string, dtype, shape = serialise_array_b64(arr)
-    return {
-        "@type": "ndarray",
-        "dtype": dtype,
-        "shape": shape,
-        "base64": b64_string
-    }
+    return {"@type": "ndarray", "dtype": dtype, "shape": shape, "base64": b64_string}
 
 
 def json_to_ndarray(json_dict: dict):
@@ -42,9 +37,10 @@ def json_to_ndarray(json_dict: dict):
     for required_param in ("dtype", "shape", "base64"):
         if not json_dict.get(required_param):
             raise KeyError(f"Missing required key {required_param}")
-    
-    return deserialise_array_b64(json_dict.get("base64"), json_dict.get("dtype"), json_dict.get("shape"))
 
+    return deserialise_array_b64(
+        json_dict.get("base64"), json_dict.get("dtype"), json_dict.get("shape")
+    )
 
 
 @contextmanager