Over the past few years, we’ve seen an explosion of new security products and features. This has impacted everything from surveillance cameras and recording devices to the wiring and connectors used in today’s camera systems. We have left the VCR and analog days and plunged headfirst into the digital age, complete with a whole new set of rules, opportunities and language. And as with everything else in life, about the time you think you understand it, it will change.
There are still three major components to consider with closed-caption television (CCTV) systems: cameras, storage devices and monitors. Let’s look at these components in detail as well as the differences between analog, digital and Internet protocol (IP)-type models.
We now have the ability to connect almost any video monitor to a CCTV system. This includes flat and plasma screens and LCD monitors. This is one of the best improvements in CCTV. You can have great cameras and recording devices, but if the monitor is not of the same quality, you’ll still have a system that is not up to speed.
With the cost of flat screens dropping, you can afford to have a large screen or several mid-size monitors for the same price as a conventional CCTV monitor. Most recording devices will accept VGA, S-Video and composite video output. This gives users unlimited choices. Because the monitors can be mounted on the wall, we now have more desk and counter space. Be careful, however, and invest in a quality monitor, not a low-end budget model.
The biggest improvement in cameras has been in picture quality and the ability to see in low-light conditions. With the coming of the digital technology, we have gone from 320 lines of resolution to more than 500. This gives us the same result as high-definition (HD) for our camera systems. Picture quality is markedly better than with analog cameras, even if the rest of the system is still analog.
The main difference between analog and digital cameras is the use of digital chips or imaging devices. These allow for a picture to be transmitted in digital format much like digital TV. If you are looking to upgrade your system, consider improving all your equipment. Any new installations should be done using digital equipment with no exceptions.
Many cameras also have night-vision abilities by using two technologies. The first is infrared (IR) illuminators. These are small, LED-type lights that illuminate the picture field of view, allowing the camera to see in almost total darkness. These LEDs have a soft glow and do not emit any visible light.
When looking at this technology, look at the number of LEDs and the specified range. Some cameras rate for distance farther than 50 feet, but the picture quality tends to be grainy and the image may not be useful. The other consideration for IR is they have a tendency to over illuminate reflective materials. This means items such as license plates will be too bright to be viewable. This does not mean you shouldn’t use IR illumination, just be aware of the limits.
IR technology is gaining ground, and there are now numerous low-cost IR cameras with great quality and reliability. If you lack good lighting on your site, changing your cameras to IR-type will make a big difference in what you see.
The second type of technology used for low light is digital intensifiers. This is where we really see a difference in what digital has brought to the camera side of the equation. By using digital technology, we are able to enhance the picture and boost the light the camera sees.
Cameras can see in almost total darkness. We measure the light a camera needs to see in lux. A lux of 0.27 would be a full moon on a clear night; 0.01 is a quarter moon on a clear night, and .002 is a moonless night sky. Analog cameras cannot see below about .02 and are grainy at this level. Digital IR can see at .002 but, again, at these levels, the picture is grainy. Digital-intensified cameras can see in .003 and the picture is usable.