The recommended lens angle for outdoor surveillance depends on the specific requirements of the area being monitored. Generally, a wide-angle lens is preferred for outdoor surveillance as it provides a broader field of view and enables monitoring of a larger area. A wider angle lens also helps to capture more details and provides a better situational awareness. However, it is important to note that a wider angle lens can also result in more distortion and reduce the clarity of the image.
On the other hand, a narrower angle lens such as a telephoto lens can be used to monitor a specific area with more detail, such as a parking lot or a building entrance. This type of lens is especially useful when the area being monitored is far away from the camera. In general, selecting the appropriate lens angle for outdoor surveillance involves balancing the need for a wider field of view with the need for clarity and detail in specific areas.