diff --git a/apps/app_full.py b/apps/app_full.py
index dc3e6711..3bd49bab 100755
--- a/apps/app_full.py
+++ b/apps/app_full.py
@@ -1180,6 +1180,7 @@ def toggle_hidden_controls():
     "AfWindows",
     "AfPause",
     "AfMetering",
+    "ScalerCrops"
 }
 
 # Main widgets
diff --git a/picamera2/configuration.py b/picamera2/configuration.py
index 7c6a3f2d..9c01794b 100644
--- a/picamera2/configuration.py
+++ b/picamera2/configuration.py
@@ -83,7 +83,7 @@ def align(self, optimal=True):
 
 
 class StreamConfiguration(Configuration):
-    _ALLOWED_FIELDS = ("size", "format", "stride", "framesize")
+    _ALLOWED_FIELDS = ("size", "format", "stride", "framesize", "preserve_ar")
     _FIELD_CLASS_MAP = {}
     _FORWARD_FIELDS = {}
 
diff --git a/picamera2/picamera2.py b/picamera2/picamera2.py
index cabfbb16..67e76e30 100644
--- a/picamera2/picamera2.py
+++ b/picamera2/picamera2.py
@@ -650,7 +650,7 @@ def _make_initial_stream_config(stream_config: dict, updates: dict, ignore_list=
         """
         if updates is None:
             return None
-        valid = ("format", "size", "stride")
+        valid = ("format", "size", "stride", "preserve_ar")
         for key, value in updates.items():
             if isinstance(value, SensorFormat):
                 value = str(value)
@@ -687,9 +687,9 @@ def create_preview_configuration(self, main={}, lores=None, raw={}, transform=li
         if not self._is_rpi_camera():
             raw = None
             sensor = None
-        main = self._make_initial_stream_config({"format": "XBGR8888", "size": (640, 480)}, main)
+        main = self._make_initial_stream_config({"format": "XBGR8888", "size": (640, 480), "preserve_ar": True}, main)
         self.align_stream(main, optimal=False)
-        lores = self._make_initial_stream_config({"format": "YUV420", "size": main["size"]}, lores)
+        lores = self._make_initial_stream_config({"format": "YUV420", "size": main["size"], "preserve_ar": False}, lores)
         if lores is not None:
             self.align_stream(lores, optimal=False)
         raw = self._make_initial_stream_config({"format": self.sensor_format, "size": main["size"]},
@@ -721,9 +721,9 @@ def create_still_configuration(self, main={}, lores=None, raw={}, transform=libc
         if not self._is_rpi_camera():
             raw = None
             sensor = None
-        main = self._make_initial_stream_config({"format": "BGR888", "size": self.sensor_resolution}, main)
+        main = self._make_initial_stream_config({"format": "BGR888", "size": self.sensor_resolution, "preserve_ar": True}, main)
         self.align_stream(main, optimal=False)
-        lores = self._make_initial_stream_config({"format": "YUV420", "size": main["size"]}, lores)
+        lores = self._make_initial_stream_config({"format": "YUV420", "size": main["size"], "preserve_ar": False}, lores)
         if lores is not None:
             self.align_stream(lores, optimal=False)
         raw = self._make_initial_stream_config({"format": self.sensor_format, "size": main["size"]},
@@ -755,9 +755,9 @@ def create_video_configuration(self, main={}, lores=None, raw={}, transform=libc
         if not self._is_rpi_camera():
             raw = None
             sensor = None
-        main = self._make_initial_stream_config({"format": "XBGR8888", "size": (1280, 720)}, main)
+        main = self._make_initial_stream_config({"format": "XBGR8888", "size": (1280, 720), "preserve_ar": True}, main)
         self.align_stream(main, optimal=False)
-        lores = self._make_initial_stream_config({"format": "YUV420", "size": main["size"]}, lores)
+        lores = self._make_initial_stream_config({"format": "YUV420", "size": main["size"], "preserve_ar": False}, lores)
         if lores is not None:
             self.align_stream(lores, optimal=False)
         raw = self._make_initial_stream_config({"format": self.sensor_format, "size": main["size"]},
@@ -1116,6 +1116,15 @@ def configure_(self, camera_config="preview") -> None:
         self.controls = Controls(self, controls=self.camera_config['controls'])
         self.configure_count += 1
 
+        if "ScalerCrops" in self.camera_controls:
+            par_crop = self.camera_controls["ScalerCrops"]
+            full_fov = self.camera_controls["ScalerCrop"][1]
+            scaler_crops = [par_crop[0] if camera_config["main"]["preserve_ar"] else full_fov]
+            if self.lores_index >= 0:
+                scaler_crops.append(par_crop[1] if camera_config["lores"]["preserve_ar"] else scaler_crops[0])
+            self.set_controls({"ScalerCrops": scaler_crops})
+
+
     def configure(self, camera_config="preview") -> None:
         """Configure the camera system with the given configuration."""
         self.configure_(camera_config)
diff --git a/tests/crop_test.py b/tests/crop_test.py
new file mode 100644
index 00000000..38e68029
--- /dev/null
+++ b/tests/crop_test.py
@@ -0,0 +1,24 @@
+#!/usr/bin/python3
+
+# Test setting the "preserve_ar" stream configuration flag
+
+import cv2
+
+from picamera2 import Picamera2
+
+picam2 = Picamera2()
+
+for m, l in [(False, False), (False, True), (True, False), (True, True)]:
+    cfg = picam2.create_video_configuration(main={"size": (1920, 1080), "format": 'XRGB8888', "preserve_ar": m},
+                                            lores={"size": (640, 640), "format": 'XRGB8888', "preserve_ar": l},
+                                            display="main")
+    picam2.configure(cfg)
+    picam2.start(show_preview=True)
+
+    for _ in range(100):
+        im = picam2.capture_array("lores")
+        cv2.imshow("lores", im)
+        cv2.resizeWindow("lores", (640, 640))
+        cv2.waitKey(1)
+
+    picam2.stop()
diff --git a/tests/test_list.txt b/tests/test_list.txt
index cd2cafaf..b26c6e12 100644
--- a/tests/test_list.txt
+++ b/tests/test_list.txt
@@ -62,6 +62,7 @@ tests/colour_spaces.py
 tests/config_with_sensor.py
 tests/configurations.py
 tests/context_test.py
+tests/crop_test.py
 tests/display_transform_null.py
 tests/display_transform_qt.py
 tests/easy_video2.py