diff --git a/picamera2/formats.py b/picamera2/formats.py
index 348ce642..85a4e5b4 100644
--- a/picamera2/formats.py
+++ b/picamera2/formats.py
@@ -11,7 +11,7 @@
                  "BGGR16_PISP_COMP1", "GBRG16_PISP_COMP1", "GRBG16_PISP_COMP1", "RGGB16_PISP_COMP1",
                  "SBGGR16", "SGBRG16", "SGRBG16", "SRGGB16", }
 
-MONO_FORMATS = {"R8", "R10", "R12", "R8_CSI2P", "R10_CSI2P", "R12_CSI2P"}
+MONO_FORMATS = {"R8", "R10", "R12", "R16", "R8_CSI2P", "R10_CSI2P", "R12_CSI2P"}
 
 ALL_FORMATS = YUV_FORMATS | RGB_FORMATS | BAYER_FORMATS | MONO_FORMATS
 
diff --git a/picamera2/picamera2.py b/picamera2/picamera2.py
index ec60e7d7..caff2cf0 100644
--- a/picamera2/picamera2.py
+++ b/picamera2/picamera2.py
@@ -238,6 +238,9 @@ def __init__(self, camera_num=0, verbose_console=None, tuning=None, allocator=No
             os.environ.pop("LIBCAMERA_RPI_TUNING_FILE", None)  # Use default tuning
         self.notifyme_r, self.notifyme_w = os.pipe2(os.O_NONBLOCK)
         self.notifymeread = os.fdopen(self.notifyme_r, 'rb')
+        # Set these before trying to open the camera in case that fails (shutting stuff down may check them).
+        self._preview = None
+        self.is_open = False
         # Get the real libcamera internal number.
         camera_num = self.global_camera_info()[camera_num]['Num']
         self._cm.add(camera_num, self)
@@ -279,9 +282,7 @@ def camera_manager(self):
 
     def _reset_flags(self) -> None:
         self.camera = None
-        self.is_open = False
         self.camera_ctrl_info = {}
-        self._preview = None
         self.camera_config = None
         self.libcamera_config = None
         self.streams = None