diff --git a/pykick/detection_demo.py b/pykick/detection_demo.py
index e4220ce..d0569ee 100644
--- a/pykick/detection_demo.py
+++ b/pykick/detection_demo.py
@@ -5,7 +5,7 @@ import argparse
 
 import cv2
 
-from .utils import read_config, imresize, field_mask
+from .utils import read_config, imresize
 from .imagereaders import NaoImageReader, VideoReader, PictureReader
 from .finders import BallFinder, GoalFinder, FieldFinder
 
@@ -100,10 +100,9 @@ if __name__ == '__main__':
             frame = imresize(frame, width=args.width)
 
             field = field_finder.find(frame)
-            not_field = cv2.bitwise_not(field)
 
-            ball_frame = field_finder.draw(frame, field)
-            goal_frame = field_finder.draw(frame, not_field)
+            ball_frame = field_finder.mask_it(frame, field)
+            goal_frame = field_finder.mask_it(frame, field, inverse=True)
 
             ball = ball_finder.find(ball_frame)
             goal = goal_finder.find(goal_frame)
diff --git a/pykick/finders.py b/pykick/finders.py
index 08e7424..2db0b5f 100644
--- a/pykick/finders.py
+++ b/pykick/finders.py
@@ -29,13 +29,22 @@ class FieldFinder(object):
             return None
         field = max(cnts, key=cv2.contourArea)
         field = cv2.convexHull(field)
-        mask = np.zeros(thr.shape, dtype=np.uint8)
-        cv2.drawContours(mask, (field,), -1, 255, -1)
-        return mask
+        return field
 
     def draw(self, frame, field):
         if field is not None:
-            frame = cv2.bitwise_and(frame, frame, mask=field)
+            frame = frame.copy()
+            cv2.drawContours(frame, (field,), -1, (0, 0, 255), 2)
+        return frame
+
+    def mask_it(self, frame, field, inverse=False):
+        if field is not None:
+            print(frame.shape)
+            mask = np.zeros(frame.shape[:2], dtype=np.uint8)
+            cv2.drawContours(mask, (field,), -1, 255, -1)
+            if inverse:
+                mask = cv2.bitwise_not(mask)
+            frame = cv2.bitwise_and(frame, frame, mask=mask)
         return frame
 
 
diff --git a/pykick/nao_defaults.json b/pykick/nao_defaults.json
index a0ec935..d5150fe 100644
--- a/pykick/nao_defaults.json
+++ b/pykick/nao_defaults.json
@@ -29,11 +29,11 @@
     "field": [
         [
             19, 
-            57, 
-            84
+            51, 
+            60
         ], 
         [
-            65, 
+            67, 
             255, 
             255
         ]
diff --git a/pykick/striker.py b/pykick/striker.py
index f76c5f9..924b186 100644
--- a/pykick/striker.py
+++ b/pykick/striker.py
@@ -1,6 +1,8 @@
 from __future__ import print_function
 from __future__ import division
 
+import argparse
+from threading import Thread
 from math import pi
 from time import sleep, time
 
@@ -8,9 +10,7 @@ from .utils import read_config
 from .imagereaders import NaoImageReader
 from .finders import BallFinder, GoalFinder
 from .movements import NaoMover
-import argparse
 from naoqi import ALProxy
-from threading import Thread
 
 
 class Striker(object):
@@ -72,7 +72,7 @@ class Striker(object):
         """Detect the ball and return its angles in camera coordinates."""
         try:
             ball = self.ball_finder.find(cam.get_frame())
-        except RuntimeError as e:
+        except RuntimeError as e:  # Sometimes camera doesn't return an image
             print(e)
             return None