I have a double glazed porch where I would like to install an additional camera to enable me to see who is ringing the front door bell. I am disabled and had a D1 system installed with 4 cameras a fitted, the Digital Recorder has capacity for 5 more cameras. I need one inside the porch looking through the double glazed door to see who is at the door , but I have been unable to overcome the reflection from the glass which blinds the camera. Can you help please.