Megapixel cameras see great amounts of detail, but require a carefully selected supporting cast of storage, networks and displays for an outstanding performance. A&S finds out from experts how to set up video systems for real-life megapixel surveillance, as well as how to specify cameras.
Megapixel cameras see great amounts of detail, but require a carefully selected supporting cast of storage, networks and displays for an outstanding performance. a&s finds out from experts how to set up video systems for real-life megapixel surveillance, as well as how to specify cameras.
Most megapixel demonstrations take place outdoors on bright cloudless days, giving endless vistas of crystalclear detail. While some indoor installations also require a high level of detail, most spaces do not require the wider range of view. “Indoor megapixel surveillance is less impressive because of the close distance,” said Patrick Lim, Director of Sales and Marketing for Ademco Far East. “Outdoor, wide-area surveillance sees the most distinctive requests and appeal for megapixel.”
Sensitivity levels on the camera's spec sheet need to be taken with a grain of salt, as they still require added lighting. “When it comes to comparing camera sensitivity at low-lux lighting levels, be careful, they usually refer to the light at the sensor, not the ambient lighting in any given scene,” said Mark Wilson, VP of Marketing, Infinova. “To get these lux levels at the sensor, the ambient lighting at the scene may have to be many times more.”
Scalability
Megapixel surveillance expansion is relatively simple, as new devices are generally configured by the VMS. “With an IP system, you can add or move a camera by simply mounting it and plugging in a single structured cable to deliver all video, bidirectional data and PoE,” said Becky Zhou, APAC Sales Director for Arecont Vision. “In most cases, an IP address is automatically assigned upon detection of the new network edge device and you're in business.”
Large-scale sites usually have network infrastructure in place to support megapixel-camera expansion. “You can scale a system easily if all the information travels over the same Ethernet cables,” said Ian Johnston, CTO of IQinVision. “With an IP-centric design, security video, VOIP telephone calls, physical access control systems as well as their conventional LAN data traffic are all combined on the same network. This enables large enterprises to focus their dollars on one department — IT — and gain huge benefits across the board.”
Bandwidth
Scalability depends on how many devices are on the network. A small system simply requires an NVR and basic switch, with bandwidth generally not being a problem, but gets more complex with more cameras. “Once you're over 100-plus cameras, you have to think carefully about how to manage network bandwidth,” said Andrew Pigram, Technical Director at Norbain. “Systems of this size will probably demand multiple places to view and record. You need to think about the camera, multicast and what kinds of switch protocol to minimize bandwidth and get information sent to the right location.”
Compression has a direct effect on bandwidth and recording, as not all recording platforms support H.264 or MPEG-4 compression for third-party megapixel cameras. “For a remote island facility, if you remotely connect to the site, on some platforms not all codecs are available to a remote user,” said Stephen Moody, Security Development Manager for ViS Security Solutions. “Bandwidth implications come into play. You would have to start prioritizing the network to make sure you're getting the proper flow of traffic. Using quality of service applications often rectifies this and provides you with the correct bandwidth suitable for the application, even if the codec is not remotely supported.”