Infinova: How and Why to Select Megapixel, Network and Analog Security Cameras (Part 1)

A commonsense guide for chief security officers (CSOs), directors and managers on how to maximize the effectiveness of your surveillance solution by selecting the right combination of cameras for the task.

Types of Cameras
Basically there are two general types of cameras: Fixed and PTZ. There are also two types of camera technology: analog and network cameras. Fixed cameras are not as complicated as PTZ models, which, on one hand, can simplify the selection process as well as migration. On the other hand, because fixed cameras have fewer features and adjustments, it's crucial to have or buy the right lens for a specific application with them.

Most installations use both fixed and PTZ cameras, depending on needs. On average, PTZ cameras cost more than fixed cameras. And because PTZ cameras generally are larger than fixed cameras, fixed cameras may appeal to end users needing aesthetics along with security. For example, there are fixed minidome cameras, measuring only a handful inches in diameter, for installations where appearance is a chief consideration. In comparison with traditional fixed cameras, the dome adds an extra level of protection from bumps and cleaning crews.

If a camera is outdoors, there are many options. One is use of a day/night unit. When the camera senses that it is nighttime, there is a boost in sensitivity. And it switches to monochrome. Another option centers on thermal imaging, night vision and infrared cameras. Often this approach includes infrared illumination, which is achieved through LEDs installed inside the housing. When selecting IR illumination, one rule of thumb from the A&E folks is one foot per LED. The downside: If something gets too close to the camera, it can create a bright flash in the image.

Megapixel and HD
As compared to standard definition cameras, emerging are megapixel and HD network cameras. Not all megapixel cameras are HD but all HD cameras are megapixel. HD cameras are megapixel cameras but also meet HDTV standards. As with so much in the security camera sector, it all depends on pixels – the number of them in this case.

In the early 2000s, a changing of the guard occurred in the electronics industry. Standard definition, which had been the de facto technology for many decades, was joined by HD. Standard definition (SD) refers to a digital video signal at either 640 by 480 or 704 by 480 lines of resolution.

Megapixel network cameras for security surveillance and remote monitoring applications boast more resolution and, therefore, higher quality images. Megapixel units can range from 1.3 to 5 and higher. For most applications, the work horse is the 1.3 megapixel camera. There are more of these than any others installed. It's the cost-effective hook – in addition to price, 1.3 megapixel cameras give 2x the horizontal view of a standard definition camera.

The very high megapixel cameras such as 7, 10, and 14 are aimed at special applications and are not intended for general surveillance. They require more bandwidth and more storage, and the higher resolutions often do not operate at high frame rates from one to two fps.

Advantages beyond Analog
Still, increasing the detail or the "to be monitored" area above analog capabilities is an advantage. The large image format enables the camera to capture greater detail or offer a wider field of view. Megapixel IP video is digital data that takes up bandwidth so bandwidth management is essential in designing a cost effective IP video system. Most IP cameras have built in bandwidth management, though.

There also are diminishing returns when megapixel camera images are viewed on most monitors. Maximum resolution of the monitor is what you see from the cameras. So with megapixel cameras the higher resolutions look the same. The true benefit of higher megapixel resolution is in use of digital zoom.

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