The mainstreaming of low-light surveillance cameras

The number of video surveillance cameras equipped with advanced low-light functionality is set to soar over the next four years, according to a recent report from IHS Markit.

In 2015 approximately 4.75 million of such cameras were delivered to market – which is projected to rise to about 51 million by 2022.

The good news for system integrators and their end-user clients is that, through economies of scale and increased competition, the price of these cameras is likely to gradually fall. This will eventually make them affordable for virtually any video surveillance project and thus fuel the growth in the number deployed.

Conversely, it’s bad news for intruders who would normally use the cloak of darkness to break into a site, as end users can deploy high definition cameras that capture identification-grade images in very low light conditions.

What do we mean by advanced low-light camera capability?

Well, as an example, a recently launched bullet camera is being supplied with the world’s first 0.94 f-stop lens. Combined with sens-i technology built into the camera’s new sensor, it delivers noiseless, clear colour images when light levels are as low as 0.004Lux. This means there will be few situations where the camera’s built-in IR illumination will be required.

Nice or necessary?

Human beings can observe objects and activity in relatively low lighting conditions thanks to the complex processing which goes on between the eye and brain. Until recently, video surveillance cameras have not shared anything close to this phenomenal processing power and have therefore struggled to deliver quality images in challenging lighting conditions. 

Green issues such as light pollution and energy costs, as well as capital and installation costs associated with the provision of supplementary lighting, have significantly increased demand for the latest generation of video surveillance cameras that can generate evidence-grade images in very low light conditions.

Although many of these cameras feature built-in IR LED illumination, these alone will not satisfy requirements for all video surveillance applications.

Where, for example, cameras have been installed for covert surveillance purposes, the red light emanating from LEDs are likely to give the game away to unwanted intruders well before a control room operator can alert security guards or the police. For safety reasons, railway operators will not deploy cameras with red IR illumination.

Nevertheless, they are growing in popularity and understandably so, as built-in IR LEDs, which consume minimal energy and are automatically activated, can (depending on the model) provide effective lighting up to a distance of 100 metres.

On some of the latest generation of cameras, the IR intensity is automatically adjusted to provide the appropriate level of IR light depending on zoom ratio, while some ‘flateye’ cameras have a flat surface cover, which is applied to the front of the lens instead of the dome cover. This reduces ‘diffused reflection’, caused by moisture, and in the absence of a normal transparent dome cover, removes the deleterious effect scratches can have on image clarity.

Specification

There isn’t a single answer to the difficulties presented by low light environments, but with the right advice, designing a video surveillance solution to cope with the challenge should not be a difficult task.

A combination of high resolution and low sensitivity is vital, but it’s also important that cameras have performance enhancing features and functions, such as Wide Dynamic Range (WDR), Automatic Gain Control (AGC) and Sense-Up.

The lens used must also match the camera’s performance, thereby getting as much light as possible onto the image sensor.

It obviously makes sense to work with a manufacturer that is prepared to back its confidence in its low light cameras by being prepared to carry out a live on-site demonstration. It is certainly worth taking the time to research various options so you don’t make a hasty decision and suffer buyer’s remorse.

There is no shortage of cameras to choose from, but these can be filtered by seeking advice from a systems integrator or the technical department of the distributor they source cameras from.