A telephoto lens is a type of camera lens with a long focal length, allowing for magnification and capturing distant subjects in detail. It has a narrow field of view, which results in a close-up view of the subject, making it ideal for surveillance applications where long-range monitoring is required. Telephoto lenses are commonly used in security cameras to monitor focused areas such as hallways or alleys.
Manual zoom is typically not available after a camera's installation. Some cameras are PTZ cameras (pan/tilt/zoom) which can be controlled remotely. However, most cameras are fixed and would need a technician to change the positioning and angle.