diff --git a/openflexure_microscope/microscope.py b/openflexure_microscope/microscope.py
index 7c987161..eb36efd6 100644
--- a/openflexure_microscope/microscope.py
+++ b/openflexure_microscope/microscope.py
@@ -42,9 +42,12 @@ class Microscope(object):
         if attach_plugins:
             self.attach_plugins()
         
-        # Get name from config, or generate
+        # Set default parameters
         if not 'name' in self._config:
             self._config['name'] = uuid.uuid4().hex
+        
+        if not 'fov' in self._config:
+            self._config['fov'] = [0, 0]  # Assumes pi camera 2, and 40x objective
 
     def __enter__(self):
         """Create microscope on context enter."""
diff --git a/openflexure_microscope/microscoperc.default.yaml b/openflexure_microscope/microscoperc.default.yaml
index 3c10e6ce..8394b41a 100644
--- a/openflexure_microscope/microscoperc.default.yaml
+++ b/openflexure_microscope/microscoperc.default.yaml
@@ -7,6 +7,9 @@ video_resolution: [832, 624]
 image_resolution: [2592, 1944]
 numpy_resolution: [1312, 976]
 
+# Field of view, in stage steps
+fov: [4100, 3146]
+
 # Capture quality
 jpeg_quality: 75