OutbackCam: Why detection angle different to viewing angle
The OutbackCam utilizes a passive infrared motion sensor so that the system is able to run in a stand-by mode. This means the battery life of the system is extended from what would otherwise be hours, into weeks and/or months. When activity is detected by the motion sensor, the camera component that was previously switched off is now activated and takes one or more snapshots. Due to the time difference between when motion is detected and when the camera is able to take its first photo, we have extended the detection angle so that an object moving through the shot will be captured despite the activation delay.
Having said that, passive infrared motion detection is not a flawless technology. You will get times where the sensor detects motion when there is none. When passive infrared motion detectors are used outdoors, there is a higher likelihood of false alarms due to a large number of varying environmental variables such as temperature, wind speed, time of day and lighting conditions.
If you believe this renders the system unusable, you could try using race tape (a.k.a. gaffer tape) to tape either side of the white passive infrared sensor until you have an acceptable detection angle.