Global Security Tracking

Camera Basics

There are two basic video camera capturing technologies in use today, analog and digital with the latter being the newest in technology. CMOS or CCD semiconductor chips are typically the camera sensors used in either analog or digital technologies to capture visible light. Cameras capture images and convert those images into electronic signals which can be either stored or viewed real-time. Both analog or digital technologies actually capture the image in analog format. CMOS chips output the image in digital format, which is either converted to analog or stored as digital. CCD chips output in analog format, which is then either saved in analog format or converted to digital.

When stating analog or digital technologies, what is really meant is the format in which the data is transfered, stored and/or viewed. Several years back analog video signals coming from the analog cameras was sent to a multiplexer located in the security office, then recorded to VCR's which record data in linear analog format to magnetic tapes. As the technologies changed, saving the data in digital format proved to have many benefits, so VCR's were replaced with DVR's (digital video recorder). Analog cameras are still in use and being sold, however, a DVR is required to convert and save the data in digital format. CD's, DVD's, and hard drives are the components used inside the DVR when saving digital data.

Analog vs IP (internet protocol) Cameras

The image capture components used between digital (IP) and analog cameras are similar. The output format between the two is what make the difference. Analog cameras send video signals out in NTSC or PAL formats, which are television standards. The video signal is carried on a single cable (of different types) which is routed back to the physical location of the CCTV's DVR and connected to available ports. The video signal is converted into a digital format and recorded for later use or instant viewing.

IP cameras output in true digital format. The video image captured by the camera is converted, compressed and encoded into an MPEG-4/H.264 industry standard and readied for transfer. The transport used by IP cameras to transfer the digital data is the same used around the world by the world wide internet. An IP camera usually includes a RJ45 connector which is used to connect to a CAT5/Ethernet IP LAN or WAN (local area network / wide area network). In order to communicate on the network each IP camera requires an unique IP address. The digital data can then be sent to the CCTV's NVR (network video recorder) server which is located somewhere on the network (LAN or WAN) where the data can be saved on hard disk or viewed.

Which technology is the best fit for your CCTV system?

Both analog camera / DVR or IP camera / NVR combinations have different pros and cons, so to determine which solution is best for your business or home, depends on your physical and individual requirements.

Contact GST for information about which camera solution is best for you!

Camera Styles

Businesses have increasingly turned to surveillance cameras. Whether it’s part of a big brother society, or just a need to secure premises against would-be thieves or attackers, security cameras can be a real boon inside your location. In fact, as the head of loss prevention for a leading consumer electronics retailer mentioned to me at a recent conference, business owners are finding they can use security cameras not only for security or shoplifting investigation purposes, but also to help sales staff review traffic patterns and count business traffic. Most security cameras are being placed indoors (that’s where the money and the goods are, right?). If you’re looking for a video surveillance system, consider the following types of indoor security cameras:

Bullet security cameras

The smallest of “normal” security cameras, the bullet security cam is easy to install and popular with users who want surveillance to be somewhat covert, or simply don’t want to disrupt architectural factors. A number of bullet cameras also come with “night vision” infrared LEDs to allow the camera to see in the dark – the light is visible to the camera, but not the human eye.

Traditional fixed security cameras

Fixed indoor security cam systems are mounted in one location and are set to look at a particular area, such as a cash register, an entry door or a stockroom. Larger than bullet cameras, they tend to offer better image quality because they can allow more room for image processing chips inside. Options include standard resolution, high resolution, black-and-white (a.k.a. monochrome) and color. If used indoors, they often don’t need protective housings, but can be mounted in such units if the situation calls for it.

Dome security cameras

These cameras are covered by a protective dome that helps limit dust and grime. They can be set up as “fixed” – meaning they point in one location — or they can be integrated with motors to pan, tilt and zoom.

PTZ (pan, tilt and zoom) security cameras

Mounted in central locations, security operators can use a joystick or keyboard to control where a PTZ indoor security camera looks. When shopping for a PTZ security cam, compare how much they can pan, how much they can tilt, and how fast they can move around the scene. Some are slow; some are lightening fast.

Covert security cameras

Covert “spy” security cameras are so small that they can be hidden in a number of common devices, such as clocks. Covert cameras are typically only added to a camera system when investigation of a particular crime is being pursued.

Network security cameras

Network security cameras come in a variety of forms, including those mentioned above, and are solely distinguished by the fact that they communicate their data across a TCP/IP network connection. These systems integrate easily with remote monitoring from your Internet-connected PC.

Wireless

Wireless indoor security cameras use common frequencies to transmit video over short distances to a receiver. Most need a designated receiver. These typically are of the DIY variety, and aren’t used as permanent solutions. Beware of interference, but these cameras can be applied in a pinch when running cable isn’t practical. Wireless outdoor security cameras are advancing rapidly, as well.