Day: July 7, 2018

It seems that everywhere you look, there is a surveillance camera looking back at you. Video surveillance has become an absolute necessity for every type of organization – whether it be retail, hospitality, gaming, education, infrastructure or government – or any other type of business. When a crime is committed or a tragedy occurs, there is now an expectation that it will have been recorded on video, and this usually proves to be true. As a society, we have come to depend on this video to provide us with the documentation we need in many different types of situations. However, our video surveillance systems are under constant attack. Every day, thousands of video cameras are knocked out of service, not by criminals with evil intent, but by something much more lethal and simple i.e., power surges. In fact, between normal fluctuations of power, lightning strikes and other power disruptions, virtually every video surveillance camera is at risk of going out of service either temporarily or permanently. When your surveillance system experiences a power surge, there are three possible negative outcomes: damage, destruction and downtime. A damaged or destroyed system requires repair or replacement, which can be extremely costly and time-consuming. But the downtime caused by this damage or destruction is by far the worst consequence of power surges. When a video surveillance system is no longer functional, it has much wider consequences for the organization that put it into place. When surveillance systems stop functioning, it becomes more difficult for security teams to do their jobs effectively. If there is a theft or other crime committed while video cameras are down, it will be much more difficult to identify the criminal without video of the incident. Hazardous situations like an ice patch on an outside walkway could go unnoticed while numerous individuals lose their footing on the spot, until someone falls, breaks an arm and sues the company. Liability will rise accordingly without video to confirm whether a claim is false. Facilities must be evacuated when the fire alarm systems stop functioning. When security systems are out of service, parking lots, doors, and secure areas may need to be patrolled by temporary guards at an additional cost. There is also a loss of productivity if staff is delayed by congestion and manual processes at entrances, or if their work equipment and/ or work data is damaged or lost. Downtime can also cause a potential loss of customer confidence and business volume. If a customer uses social media to complain about a website being down for a few hours, the resulting negative impact can be detrimental to a business for an extended time. To help avoid this type of situation, there are steps security professionals can take, both during the installation process and after systems are in place. Installing surge protection to keep systems up and running in the event of a power surge is simple, and as these examples show, the ROI is immense. As surveillance systems are the eyes and ears of a business, it’s crucial to keep downtime as minimal as possible. Downtime and its impact on specific verticals Billions of dollars are lost each year by businesses and other organizations due to theft, false injury claims, vandalism and more, highlighting the importance of maintaining fully operational video surveillance systems. Beyond the shared concerns of identifying criminals, providing evidence etc., downtime presents a number of different specific threats to various vertical markets. Safe cities In the past few years municipalities have become enormously dependent on surveillance video to help with in vestigations. Often this video provides the only evidence to identify individuals and prove criminal action. As more and more cities deploy video surveillance, the number of incidents where it is proven to be irreplaceable as a security resource will only continue to grow. And because so much of the infrastructure for municipal surveillance is installed outdoors in exposed locations, it is more vulnerable to the risk of downtime due to lightning strikes and other unprotected surge sources. Casinos and gaming For casinos and other gaming establishments, compliance regulations require video surveillance to be up and running 100% of the time. If video is interrupted at any time, business operations must be shut down completely, causing total loss of business revenue until the system can be repaired or replaced. No casino could survive a complete business stoppage for long – making downtime a virtually fatal situation. Higher education and K-12 The number of risk factors present on school campuses is immense – from abduction of students to vandalism or theft, and much more. For every one of these adverse events, video surveillance is of vital importance for apprehending thieves, kidnappers and other criminals; and with so many different life safety and other electronic/ electrical systems in place, the possibility rises for a power strike or surge that would cause devastating downtime. Retail Stores, malls and all types of retail establishments absolutely require their video surveillance systems to be up and running in order to protect them against losses from shoplifting, sweet-hearting, vandalism and more. Without a working surveillance system many of these crimes would simply go undetected, though their negative effect on the bottom line would be unmistakable. Retailers literally cannot afford downtime. A simple step to protect devices To avoid the possibility of downtime for the video surveillance system, it is imperative to include surge protection devices in your planning right from the start, and anytime you expand, improve or install a surveillance system. Surge protection is quite easy and reasonable in cost to add, and it is an insurance policy for your organization, providing protection from every type of power event. For video surveillance systems, it is recommended that surge protection be installed at every external camera, including outdoor PoE or PoE+ IP cameras. Surges can travel through cabling from a remote device, damage or destroy a network switch, and possibly cause further issues with other switch-connected devices such as servers running VMS software. If…

Image resolution versus field of view One important, but often neglected consideration in video surveillance systems design is the trade-off between image resolution and field of view. With any given combination of camera and lens the native resolution from the camera is spread over the entire field of view of the lens, determining pixel density and image resolution. The wider the resolution is spread, the lower the pixel density, the lower the image resolution or image detail. The images below, taken with the same camera from the same distance away, illustrate this trade-off. The widest field of view allows you to cover the widest area but does not allow you to see high detail, while the narrowest field of view permits capture of high detail at the expense of wide area coverage. The next series of images, each taken with the same high resolution camera from the same distance away similarly illustrates the trade-off of high detail and ability to identify a person when using a wide angle of view lens and the ability to cover a wide area. Other ways to improve image detail So now you see the trade-off. You would like to cover the whole area, but unfortunately you are not able to read the license plate. What to do? At this point, there are a few other variables that you may be able to change in your system design to improve image detail. First is the distance from the camera to the subject. If possible, the installer could improve the image detail by moving the camera closer to the subject. This may be feasible in a new installation, but in an existing system this may be limited by the physical constraints of the location and the system, as well as costs associated with re-cabling. Moving closer improves the image detail, but field of view is reduced. The second variable that may be changed is the camera resolution. By selecting a higher resolution camera with a higher starting number of pixels and spreading them over the same field of view as before, the pixel density will be higher and the resulting image detail will be better. Of course, this assumes you can make that change in your system and you can support the likely higher priced hardware and data storage needs required with higher resolution systems. The higher resolution, data intensive cameras will also lower the frame rate of the system which must also be kept in mind especially with industry specific standards and requirements. Use available tools There are many useful tools available to help support systems design and correct equipment selection. One of those is Theia’s own image resolution and lens calculator. The calculator allows you to input some important details of your application and potential equipment, then quickly calculates image resolution with those assumptions. You input the camera resolution and sensor size you intend to use, the lens field of view you believe you need, then input your key project variables – either how much resolution you think you need in terms of pixel density, how much coverage you need in distance (feet or meters), or how far away the camera is from the subject. The tool then calculates the other variables for you. For example, you indicate you plan to use a 5 megapixel 1/2.5” sensor camera, a 3mm lens and you will be 50 feet away from your subject. The tool will calculate your pixel density – in this case 27 pixels/ foot, and coverage width – here 97 feet wide. The tool then provides an image that represents the level of image resolution you would get for your selected variables allowing you to quickly see if you have enough resolution to meet the needs of your application. The newest iPhone and iPad versions of Theia’s calculator App include enhancements that allow users to input the camera height and/ or camera angle so that one can tell if a person’s head, for example, will be covered in the image given different distances from the camera. The latest version also allows the user to introduce a level of jpeg noise so that the resulting image more accurately reflects real world conditions. The importance of lens selection If you decide to increase your image resolution by increasing the camera resolution, you must also consider lens selection. The lens needed for an IP/ megapixel camera is much different than the lens needed for a traditional analog camera. These higher resolution cameras demand higher performance lenses in order to take full advantage of the increased resolution. For instance, in a megapixel camera, the focal plane spot size of the lens must be comparable or smaller than the pixel size on the sensor (Figures A and B below), otherwise the light falls off the pixel resulting in a fuzzy image.Using a standard resolution lens with a 5 megapixel camera will produce a blurry image. Most often if you want to take advantage of all the pixels a multi megapixel camera provides, a high quality lens with matching resolution is needed otherwise the money spent on a high resolution camera is wasted. One would assume, then, that all someone specifying a megapixel camera needs to do is specify a megapixel lens. However, it’s not that simple and in many cases it can be quite difficult to ensure that the lens needed is the lens being offered. Traditionally, just about any decent lens would do the job for traditional analog cameras so specifying the lens wasn’t a problem. As a result, too many designers and integrators are still unaware that for megapixel cameras not all lenses are created equally. In megapixel cameras the pixel size and the required lens spot size varies depending on the size of sensor and quantity of pixels it contains. You can have 2 different cameras, both 1.3 megapixel, but if the sensor size is not the same the pixel size will be different. The figures below illustrate this. In selecting a lens it…