diff --git a/axis_camera/launch/axis.launch b/axis_camera/launch/axis.launch
index dde79e4..1393841 100644
--- a/axis_camera/launch/axis.launch
+++ b/axis_camera/launch/axis.launch
@@ -13,6 +13,7 @@
   <arg name="width" default="640" />
   <arg name="height" default="480" />
   <arg name="camera" default="1" />
+  <arg name="frame_id" default="$(arg camera_name)_camera_link"/>
 
   <arg name="enable_ptz_teleop" default="0" />
   <arg name="joy_topic" default="/bluetooth_teleop/joy" />
@@ -22,21 +23,23 @@
   <arg name="fps" default="0" />
 
   <group ns="$(arg camera_name)">
-    <param name="hostname" value="$(arg hostname)" />
-    <param name="username" value="$(arg username)" />
-    <param name="password" value="$(arg password)" />
-    <param name="use_encrypted_password" value="$(arg encrypt_password)" />
-    <param name="width" value="$(arg width)" />
-    <param name="height" value="$(arg height)" />
-    <param name="camera" value="$(arg camera)" />
-    <param name="frame_id" value="$(arg camera_name)_camera_link" />
-    <param name="wiper" value="$(arg enable_wiper)" />
-    <param name="defog" value="$(arg enable_defog)" />
-    <param name="ir" value="$(arg enable_ir)" />
-    <param name="fps" value="$(arg fps)" />
-    <param name="ptz" value="$(arg enable_ptz)" />
 
-    <node pkg="axis_camera" type="axis_camera_node" name="axis" />
+    <node pkg="axis_camera" type="axis_camera_node" name="axis">
+      <rosparam subst_value="true">
+        hostname: '$(arg hostname)'
+        username: '$(arg username)'
+        password: '$(arg password)'
+        use_encrypted_password: $(arg encrypt_password)
+        width: $(arg width)
+        height: $(arg height)
+        camera: $(arg camera)
+        frame_id: '$(arg frame_id)'
+        wiper: $(arg enable_wiper)
+        defog: $(arg enable_defog)
+        fps: $(arg fps)
+        ptz: $(arg enable_ptz)
+      </rosparam>
+    </node>
 
     <node pkg="image_transport" type="republish" name="republish"
           args="compressed theora" if="$(arg enable_theora)">
diff --git a/axis_camera/nodes/axis_camera_node b/axis_camera/nodes/axis_camera_node
index 985d7f7..b4b0d6a 100755
--- a/axis_camera/nodes/axis_camera_node
+++ b/axis_camera/nodes/axis_camera_node
@@ -13,20 +13,15 @@ def updateArgs(arg_defaults):
     '''
     args = {}
     for name, val in arg_defaults.items():
-        full_name = rospy.search_param(name)
-        if full_name is None:
-            args[name] = val
+        if rospy.has_param('~' + name):
+            args[name] = rospy.get_param('~' + name)
         else:
-            args[name] = rospy.get_param(full_name, val)
-    # resolve frame_id with tf_prefix (unless already absolute)
-    if args['frame_id'][0] != '/':        # not absolute?
-        tf_prefix = rospy.search_param('tf_prefix')
-        prefix_val = ''
-        if tf_prefix is not None:           # prefix defined?
-            prefix_val = rospy.get_param(tf_prefix)
-            if prefix_val[0] != '/':          # prefix not absolute?
-                prefix_val = '/' + prefix_val
-        args['frame_id'] = prefix_val + '/' + args['frame_id']
+            args[name] = rospy.get_param(name, val)
+    # resolve frame_id with tf_prefix
+    args['frame_id'] = args['frame_id'].lstrip('/')
+    tf_prefix = rospy.get_param('tf_prefix', '').lstrip('/')
+    if tf_prefix:
+        args['frame_id'] = tf_prefix + '/' + args['frame_id']
     return(args)