Video surveillance camera technology is constantly evolving, promising increased low-light clarity through greatly enhanced minimum scene illumination performance, allied to expanded pixel counts. Although these are all impressive features that greatly improve the applications for end-users, there is an additional element that should be considered when specifying professional video surveillance, and it’s one that can either make or break an effective 24/7 surveillance solution -- specifically, supplementary lighting.
Without sufficient light, video cameras are ineffective, and their footage unusable, capturing only dark, grainy images - of no use to security staff or law enforcement personnel. By the same token, providing too much light can create ‘hot spots,’ burning out the important detail of a suspect or scene. So to help you understand why supplementary lighting for camera surveillance is so important for video monitoring, here’s a guide to the best practices for deploying it.
Background
Without adequate lighting, a clear and concise video for effective monitoring cannot be achieved. One of the key challenges that indoor and outdoor security surveillance solutions must address is a lack of light. It may be obvious, but it is still important to acknowledge that darkness greatly diminishes a camera’s ability to perform. As a result, there is far less situational awareness and a much higher chance for security blind spots to occur, which can leave people, property and assets vulnerable. Also, lack of light can effectively dismantle any chance of successfully operating advanced analytic technologies, like object tracking or intrusion detection.
While some video camera manufacturers have tried to address the need for supplementary lighting by building Light-Emitting Diode (LED)-based illuminators into their camera housings, unfortunately, today’s integrated camera/lighting options tend to fall short in several important areas. Cameras that utilize integrated lighting around the lens lack flexibility. Often, the built-in lights can only cover a comparatively short distance. Moreover, when the integrated light eventually burns out, replacing it is impossible. In this scenario, many integrators invariably end up replacing the integrated camera’s light with a separate light unit. Also, it has to be remembered that lighting can attract insects and spider webs. This has little or no effect on camera video performance when using a separate lighting unit. However, with integrated camera/light units, the issue can cause an obstruction around the lens of the camera, and even be responsible for generating false triggers/alarms for any employed video analytics.
Fortunately, there is a simple solution that can be employed to enhance the quality of surveillance lighting and is cost-effective at the same time. Good quality, independent, stand alone LED illuminators not only provide the correct amount of light disbursement for optimum camera imaging performance, but also eliminate lighting hotspots, and greatly reduce problems caused by insect build-up.
Lighting the Way
The main supplementary lighting sources are infrared (IR) and white light. Let’s take a look at their advantages and differences.
IR illuminators provide light that is invisible to the human eye but fully visible to a CCTV camera. IR illuminators can work with monochrome, and true day and night mono/color cameras. IR lighting products will not only enable a camera to pick up nighttime images clearly but due to the fact that they emit no more than a very dim glow (being almost invisible to the naked eye), they also don't attract unwanted attention. In short, IR solutions create zero light pollution, provide long distance illumination to optimize camera performance, and yield low running costs.
White light illuminators can be used with all cameras; however, they allow a camera to see in color 24/7. In recent years, there has been a global shift in lighting from incandescent bulbs to LEDs. These LEDs provide low running cost, uniform illumination, extremely long lifespan, and are incredibly durable and insensitive to vibration. In fact, by switching to LED-based illuminators, organizations have saved thousands of dollars each year in energy costs, while increasing their site security. LED white light, unlike the more standard incandescent sources, closely simulates daylight and will illuminate camera images, brightening any specified scene to be viewed. White light illuminators can be used to provide a welcoming environment in one setting and act as an effective crime deterrent in another.
Deployment Tips
When selecting an illuminator for a surveillance solution, there are four key factors to be taken into consideration.
- Environment: Always be mindful of the setting in which a security system is being deployed. For example, if specifying lighting for a densely populated area like an apartment complex or college campus, the effect of light pollution should be considered. Simply flooding an area with white light may actually cause more issues than solve them, so IR light should be considered. However, white light can also be used to provide visibility in dark areas, thereby improving safety in certain applications.
- Camera type: Knowing what type of camera your illuminators are pairing with is also of the utmost importance for any project. Pan-Tilt-Zoom (PTZ) cameras present a particularly unique challenge, as their ability to move cannot be matched in terms of available lighting solutions. This brings us into our next two crucial factors, the angle and distance of illuminators.
- Angle of illumination: For cameras such as PTZ, you need to match their required scene of view to obtain full coverage. Setting multiple (three), 120-degree wide-angle illuminators on a triple mounting bracket can provide complete coverage for any 360-degree camera.
- Illumination options: Lastly, illuminators don’t always have to be installed with the camera. Separate illuminators allow for better coverage of the desired region, resulting in enhanced visibility and higher image quality.
Vertical markets
Adding independent illuminators to an existing security system for 24/7 surveillance will improve its overall efficiency. However, by utilizing project-specific approaches, end-users can enhance CCTV camera performance even further. Below are a few best practices for lighting initiatives within the government, education, healthcare and safe city sectors (to name but a few).
- For government projects like border control, a wide-angle solution with long range for general purposes, and/or long range with narrow angles for fence line protection, 850nm are best. However, this is always dependent upon the application and the camera.
- When it comes to education campuses, white light illuminators are an excellent choice as they can help increase safety for staff and students by brightening dimly lit areas.
- There are many situations in which strategic lighting can be used to improve healthcare facilities, and each case requires a tailored strategy. For example, with sleep labs, 940nm IR units should be implemented in the facility. The LEDs on the 940nm units are not visible, making for a powerful but covert lighting source that will not distract subjects and disturb any kind of testing.
- In regards to safe city applications, wide angle and long-range illumination is best for general surveillance. However, for something like license plate recognition (LPR), which is a more specific application, the lighting must be a 10 or 30-degree field of view with two to three times the distance range. Additionally, the camera should be solely dedicated for LPR and the settings on the camera would need to be adjusted to allow the reflection to be obtained from the plate and light in conjunction. An 850nm IR illuminator would be best.
All-in-all, there are a number of key factors involved in specifying supplementary IR or white light illuminators for surveillance systems. However, with careful consideration of the requirements for each camera and its application needs, successful deployment of 24/7 video footage can be gained for any security system.
About the Author: Eddie Reynolds is the CEO of Iluminar, Inc.
