diff --git a/debian/changelog b/debian/changelog
index 66a0ecb..338f9d4 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,14 @@
+howdy (2.5.1) xenial; urgency=medium
+
+  * Removed dismiss_lockscreen as it could lock users out of their system (thanks @ujjwalbe, @ju916 and many others!)
+  * Added option to disable howdy when the laptop lid is closed (thanks @accek!)
+  * Added automatic fallback to default frame color palette (thanks @Ethiarpus!)
+  * Added manual exposure setting (thanks @accek!)
+  * Fixed test command ignoring dark frame threshold (thanks @eduncan911!)
+  * Fixed import error in v4l2 recorder (thanks @timwelch!)
+
+ -- boltgolt <boltgolt@gmail.com>  Fri, 29 Mar 2019 23:02:21 +0100
+
 howdy (2.5.0) xenial; urgency=medium
 
   * Added FFmpeg and v4l2 recorders (thanks @timwelch!)
diff --git a/debian/postinst b/debian/postinst
index 7ceb41c..7ab3b89 100755
--- a/debian/postinst
+++ b/debian/postinst
@@ -70,6 +70,13 @@ if not os.path.exists("/tmp/howdy_picked_device"):
 					if key == "timout":
 						key = "timeout"
 
+					# MIGRATION 2.5.0 -> 2.5.1
+					# Remove unsafe automatic dismissal of lock screen
+					if key == "dismiss_lockscreen":
+						if value == "true":
+							print("DEPRECATION: Config falue dismiss_lockscreen is no longer supported because of login loop issues.")
+						continue
+
 					try:
 						newConf.set(section, key, value)
 					# Add a new section where needed
@@ -152,24 +159,6 @@ log("Building dlib")
 
 cmd = ["sudo", "python3", "setup.py", "install"]
 cuda_used = False
-flags = ""
-
-# Get the CPU details
-with open("/proc/cpuinfo") as info:
-	for line in info:
-		if "flags" in line:
-			flags = line
-			break
-
-# Use the most efficient instruction set the CPU supports
-if "avx" in flags:
-	cmd += ["--yes", "USE_AVX_INSTRUCTIONS"]
-elif "sse4" in flags:
-	cmd += ["--yes", "USE_SSE4_INSTRUCTIONS"]
-elif "sse3" in flags:
-	cmd += ["--yes", "USE_SSE3_INSTRUCTIONS"]
-elif "sse2" in flags:
-	cmd += ["--yes", "USE_SSE2_INSTRUCTIONS"]
 
 # Compile and link dlib
 try:
diff --git a/debian/prerm b/debian/prerm
index 150e7b8..e7c2469 100755
--- a/debian/prerm
+++ b/debian/prerm
@@ -12,7 +12,7 @@ from shutil import rmtree
 if "remove" not in sys.argv and "purge" not in sys.argv:
 	sys.exit(0)
 
-# Don't try running this if it's already gome
+# Don't try running this if it's already gone
 if not os.path.exists("/lib/security/howdy/cli"):
 	sys.exit(0)
 
diff --git a/src/cli/test.py b/src/cli/test.py
index c3cbebb..16fadb1 100644
--- a/src/cli/test.py
+++ b/src/cli/test.py
@@ -1,4 +1,4 @@
-# Show a windows with the video stream and testing information
+# Show a window with the video stream and testing information
 
 # Import required modules
 import configparser
@@ -37,6 +37,10 @@ if fw != -1:
 if fh != -1:
 	video_capture.set(cv2.CAP_PROP_FRAME_HEIGHT, fh)
 
+# Read exposure and dark_thresholds from config to use in the main loop
+exposure = config.getint("video", "exposure", fallback=-1)
+dark_threshold = config.getfloat("video", "dark_threshold")
+
 # Let the user know what's up
 print("""
 Opening a window with a test feed
@@ -106,7 +110,17 @@ try:
 
 		# Grab a single frame of video
 		ret, frame = video_capture.read()
-		frame = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
+
+		try:
+			# Convert from color to grayscale
+			# First processing of frame, so frame errors show up here
+			frame = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
+		except RuntimeError:
+			pass
+		except cv2.error:
+			print("\nUnknown camera, please check your 'device_path' config value.\n")
+			raise
+
 		frame = clahe.apply(frame)
 		# Make a frame to put overlays in
 		overlay = frame.copy()
@@ -133,9 +147,6 @@ try:
 			# Draw the bar in green
 			cv2.rectangle(overlay, p1, p2, (0, 200, 0), thickness=cv2.FILLED)
 
-		# Draw a stripe indicating the dark threshold
-		cv2.rectangle(overlay, (8, 35), (20, 36), (255, 0, 0), thickness=cv2.FILLED)
-
 		# Print the statis in the bottom left
 		print_text(0, "RESOLUTION: %dx%d" % (height, width))
 		print_text(1, "FPS: %d" % (fps, ))
@@ -147,7 +158,7 @@ try:
 			cv2.putText(overlay, "SLOW MODE", (width - 66, height - 10), cv2.FONT_HERSHEY_SIMPLEX, .3, (0, 0, 255), 0, cv2.LINE_AA)
 
 		# Ignore dark frames
-		if hist_perc[0] > 50:
+		if hist_perc[0] > dark_threshold:
 			# Show that this is an ignored frame in the top right
 			cv2.putText(overlay, "DARK FRAME", (width - 68, 16), cv2.FONT_HERSHEY_SIMPLEX, .3, (0, 0, 255), 0, cv2.LINE_AA)
 		else:
@@ -156,7 +167,8 @@ try:
 
 			rec_tm = time.time()
 			# Get the locations of all faces and their locations
-			face_locations = face_detector(frame, 1) # upsample 1 time
+			# Upsample it once
+			face_locations = face_detector(frame, 1)
 			rec_tm = time.time() - rec_tm
 
 			# Loop though all faces and paint a circle around them
@@ -193,6 +205,15 @@ try:
 		if slow_mode:
 			time.sleep(.5 - frame_time)
 
+		if exposure != -1:
+			# For a strange reason on some cameras (e.g. Lenoxo X1E)
+			# setting manual exposure works only after a couple frames
+			# are captured and even after a delay it does not
+			# always work. Setting exposure at every frame is
+			# reliable though.
+			video_capture.set(cv2.CAP_PROP_AUTO_EXPOSURE, 1.0)  # 1 = Manual
+			video_capture.set(cv2.CAP_PROP_EXPOSURE, float(exposure))
+
 # On ctrl+C
 except KeyboardInterrupt:
 	# Let the user know we're stopping
diff --git a/src/compare.py b/src/compare.py
index 3f472b8..98c6b72 100644
--- a/src/compare.py
+++ b/src/compare.py
@@ -144,6 +144,9 @@ if fh != -1:
 # This will let the camera adjust its light levels while we're importing for faster scanning
 video_capture.grab()
 
+# Read exposure from config to use in the main loop
+exposure = config.getint("video", "exposure", fallback=-1)
+
 # Note the time it took to open the camera
 timings["ic"] = time.time() - timings["ic"]
 
@@ -180,10 +183,16 @@ while True:
 	# Grab a single frame of video
 	ret, frame = video_capture.read()
 
+	if frames == 1 and ret is False:
+		print("Could not read from camera")
+		exit(12)
+
 	try:
 		# Convert from color to grayscale
 		# First processing of frame, so frame errors show up here
 		gsframe = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
+	except RuntimeError:
+		gsframe = frame
 	except cv2.error:
 		print("\nUnknown camera, please check your 'device_path' config value.\n")
 		raise
@@ -261,3 +270,12 @@ while True:
 
 			# End peacefully
 			stop(0)
+
+	if exposure != -1:
+		# For a strange reason on some cameras (e.g. Lenoxo X1E)
+		# setting manual exposure works only after a couple frames
+		# are captured and even after a delay it does not
+		# always work. Setting exposure at every frame is
+		# reliable though.
+		video_capture.set(cv2.CAP_PROP_AUTO_EXPOSURE, 1.0)  # 1 = Manual
+		video_capture.set(cv2.CAP_PROP_EXPOSURE, float(exposure))
diff --git a/src/config.ini b/src/config.ini
index 34d5685..1183f48 100644
--- a/src/config.ini
+++ b/src/config.ini
@@ -15,10 +15,8 @@ suppress_unknown = false
 # Disable Howdy in remote shells
 ignore_ssh = true
 
-# Auto dismiss lock screen on confirmation
-# Will run loginctl unlock-sessions after every auth
-# Experimental, can behave incorrectly on some systems
-dismiss_lockscreen = false
+# Disable Howdy if lid is closed
+ignore_closed_lid = true
 
 # Disable howdy in the PAM
 # The howdy command will still function
@@ -70,6 +68,12 @@ device_format = v4l2
 # OPENCV only.
 force_mjpeg = false
 
+# Specify exposure value explicitly. This disables autoexposure.
+# Use qv4l2 to determine an appropriate value.
+# OPENCV only.
+exposure = -1
+
 [debug]
 # Show a short but detailed diagnostic report in console
+# Enabling this can cause some UI apps to fail, only enable it to debug
 end_report = false
diff --git a/src/pam.py b/src/pam.py
index da98cf1..3d44114 100644
--- a/src/pam.py
+++ b/src/pam.py
@@ -4,6 +4,7 @@
 import subprocess
 import sys
 import os
+import glob
 
 # pam-python is running python 2, so we use the old module here
 import ConfigParser
@@ -25,8 +26,13 @@ def doAuth(pamh):
 		if "SSH_CONNECTION" in os.environ or "SSH_CLIENT" in os.environ or "SSHD_OPTS" in os.environ:
 			sys.exit(0)
 
+	# Abort if lid is closed
+	if config.getboolean("core", "ignore_closed_lid"):
+		if any("closed" in open(f).read() for f in glob.glob("/proc/acpi/button/lid/*/state")):
+			sys.exit(0)
+
 	# Alert the user that we are doing face detection
-	if config.get("core", "detection_notice") == "true":
+	if config.getboolean("core", "detection_notice"):
 		pamh.conversation(pamh.Message(pamh.PAM_TEXT_INFO, "Attempting face detection"))
 
 	# Run compare as python3 subprocess to circumvent python version and import issues
@@ -50,11 +56,6 @@ def doAuth(pamh):
 		if not config.getboolean("core", "no_confirmation"):
 			pamh.conversation(pamh.Message(pamh.PAM_TEXT_INFO, "Identified face as " + pamh.get_user()))
 
-		# Try to dismiss the lock screen if enabled
-		if config.get("core", "dismiss_lockscreen"):
-			# Run it as root with a timeout of 1s, and never ask for a password through the UI
-			subprocess.Popen(["sudo", "timeout", "1", "loginctl", "unlock-sessions", "--no-ask-password"])
-
 		return pamh.PAM_SUCCESS
 
 	# Otherwise, we can't discribe what happend but it wasn't successful
diff --git a/src/recorders/pyv4l2_reader.py b/src/recorders/pyv4l2_reader.py
index 6d52871..d0efcf5 100644
--- a/src/recorders/pyv4l2_reader.py
+++ b/src/recorders/pyv4l2_reader.py
@@ -8,7 +8,7 @@ import sys
 from cv2 import cvtColor, COLOR_GRAY2BGR, CAP_PROP_FRAME_WIDTH, CAP_PROP_FRAME_HEIGHT
 
 try:
-	from v4l2.frame import Frame
+	from pyv4l2.frame import Frame
 except ImportError:
 	print("Missing pyv4l2 module, please run:")
 	print(" pip3 install pyv4l2\n")