Building A Better PTZ To Meet A Changing Industry

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.

PTZ Pan Tilt Zoom joystick latencyFrom 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.

Live Video Monitoring or Recording?

Live Video MonitoringAs IP video continues to gain traction in security, the capabilities of the technology are challenging some established guidelines of when to record video and when to monitor live video. Along with the technology, these standards have evolved to encompass a host of different scenarios, satisfying the diverse needs of end users in a variety of applications – from casinos and hospitals to parking garages and sports stadiums, and more.

There is little argument that the decision to monitor live video vs. record for forensic purposes should be based on the value of the assets being protected. In casinos, for example, the high cash value of potential losses makes it an easy pick for live monitoring, whereas your average commercial office building generally relies on recorded video.

Depending on the specific needs of the application, another important factor to consider is the deployment of video analytics, which can add more sophisticated levels of efficiencies and automation.

As such, many employ video recorded on motion, which reduces bandwidth consumption and the high storage costs associated with storing hundreds of hours of continuous recording each week. In some scenarios, however, this could negatively affect your security operations.

Take this example of a large urban hospital. With about 1,600 cameras all set to record on motion, the video management system was logging in excess of one million events per day. The sheer number of alarms overwhelmed security staff, and became a waste of time to attempt to clear them all, rendering the information useless.

While it’s true that a scene with little activity will produce a very small amount of data, there are a lot of variables to take into consideration. Take the difference between a camera view of an empty asphalt parking lot vs. that same parking lot shaded with many surrounding trees. The empty scene, where changes from frame to frame would be minimal, would typically produce a camera stream of as little as 0.5Mbps. In contrast, moving objects, such as leaves blowing in the wind as in the tree-filled scene, as well as low-light or shadowy conditions even during daylight hours, can havesignificant ramifications on the use of motion detection, increasing the amount of data streamed to up to 10Mbps.

Lighting is a key consideration when employing video motion detection to save on storage costs. Modern mini-dome cameras, with their own onboard IR illuminators, are typically able to counteract low-light conditions. The additional cost for the IR functionality will be more than compensated by the savings in storage and potential equipment wear and tear that can be a consequence of inadequate lighting.

As in the hospital example, trying to manage and record such a significant flow of information, particularly from high-resolution cameras, can have serious ramifications on equipment health.Triggered by factors such as poor lighting or improperly configured equipment, these large and sporadic rushes of data sent to a recording device, known as thrashing, cause it to repeatedly start and stop writing, which can significantly shorten the hard drive’s life span. Over time, this weakens the recorder’s ability to function properly.

For the hospital, an analysis of the facility’s alarm activity showed the best solution would be a hybrid approach – using motion-based recording on a scheduled basis only during certain times of the day and only on certain cameras.

In areas where analytics are deployed, the same hybrid approach can also apply very successfully. A large sports stadium that sees more than 50,000 people enter its gates within a 12-18 hour window on game day can also be easily overwhelmed with event alarms from the video management system. Simply by identifying on which cameras it was necessary to continuously record as well as monitor and during what time periods, situations of excessive alarm events can be avoided and managed successfully.

Striking that balance between continuous and motion-based recording takes a little more setup on the front end but can save in the long run on hardware wear and tear – and, ultimately, lower your cost of ownership.


How are you utilizing your security equipment to lower your cost of ownership? Please leave me a comment below.