The evolution of video surveillance cameras within the security industry has seen the technology migration from analog to digital, from low resolution to high, and now into the frontiers of high-definition.
Historically, the pan-tilt-zoom (PTZ) camera has played a role within just about every surveillance scenario because it brings to the table abilities that even the most feature-rich fixed surveillance cameras can’t replace. Typical video system installations combine fixed camera technology with PTZ functionality allowing for complete site monitoring and the capability to zoom in and track the subject when an event has occurred.
From an operator’s perspective, the resistance to migrating from analog to 1080p HD PTZ cameras is latency or response lag time when controlling an HD PTZ camera. Until now, operators believed that the joystick control experience with HD PTZ cameras was no match to the responsiveness they experienced with high performance analog PTZ cameras. In a monitored surveillance operation, when the operator moves the joystick control to pan and zoom in on and track a subject, the expectation is that the PTZ camera will respond with precision, accuracy and near zero latency. Latency has many contributing factors when you consider where the joystick control is physically located and the path the operator’s camera move-commands must travel to reach the camera. The operator requires accurate, real-time control if the HD PTZ camera is expected to follow the industry trend for replacing the analog units.
The negative effect of PTZ control latency will typically cause the operator to overshoot the target and continually make adjustments, trying to establish proper tracking on the correct Field of View (FOV). When controlling electronic devices using a joystick control, the operator tends to continue pressing the joystick until the device visually responds. In a surveillance system, control responsiveness is gauged by the video seen on a monitor. Once the operator sees the proper video, s(he) will adjust directional tracking control as needed. The existing problem with latency and high lag time is that, to deliver the proper video scene during lag time, the operator continues to send commands to the camera causing it to move beyond the desired FOV. To compensate for the lag, the operator moves the camera in the opposite direction. The latency forces the operator to make control adjustments so the scene oscillates around the target FOV but never precisely delivers what is expected.
NASA, the National Aeronautics and Space Administration, has done extensive studies to establish the maximum acceptable latency for flight control fly-by-wire systems before latency or control stick lag delays affect a pilot’s ability to properly control an aircraft. To achieve real-time control so that the lag is imperceptible to human vision and reaction time, the delay must be 200 milliseconds or less. This same level of performance is needed in surveillance systems. Today, most HD PTZ cameras have higher latency in their control delay making the tracking control not only frustrating for the operator, but often times the resulting recorded video might be missing the key situational elements.
Armed with this knowledge, what do you as an integrator or an end-user need to look for in an HD PTZ camera? You need to look for a 1080p HD PTZ camera built with high precision, solid core motors and the necessary high performance processing power to deliver the HD video with speed, precision, and accuracy. The HD PTZ camera’s capabilities are critical to achieving performance expectations. These capabilities are a combination of low latency performance and how well the camera is integrated into the recording platform. You need to look at the total solution.Whenever possible, test the camera on the system to insure the performance meets your requirements and expectations.
Too often decisions on HD PTZ cameras, like many other pieces of surveillance equipment, are made using listed specifications and pricing. It’s more beneficial to experience an HD PTZ camera’s performance and the benefits it can deliver. Before making a final investment decision, conduct a competitive comparison for yourself. You will clearly see which HD PTZ outperforms the others.
As many surveillance applications require PTZ Megapixel camera technology, it is heartening to see HD PTZ cameras being developed that can deliver this “real-time” control experience. This IP camera workhorse is steadily growing in the IP industry, adding capabilities and intelligence to meet ever-changing security demands.
Please leave me a comment below with your thoughts on HD PTZ cameras.