I just made this video (posted below) and if you look closely you can see where I cropped out the head as the 2nd layer is a different color than the first layer. I used the webcam on my macbook pro to do it... my question is... why is that line still there? does this lens change the lighting exposure or something? I tried to change the brightness and contrast but no luck, you can still see the line. Is is the camera or am I doing something wrong? Any help would be greatly appreciated.