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Speed Domes: Shrewd Performers
a&s International 2010/4/15

Slick camera performance requires interoperability of components. While meticulous design assures precise, smooth PTZ movement, robust software engineering puts speed domes to good use.

Slick camera performance requires interoperability of components. While meticulous design assures precise, smooth PTZ movement, robust software engineering puts speed domes to good use.

A speed dome system is a combination of electronic, mechanical, video and software technologies, and what customers get in the end is an integrated performance, said Alec Weingart, President of Actiontop.

With various subsystems working simultaneously, speed domes tend to have higher failure rate compared to other cameras. The procurement process usually takes longer, as buyers require time for a thorough test. "While camera procurement usually takes about a month, it is common to spend two to three months for the testing of speed domes," said James Wang, Overseas Product Manager at Dahua Technology.

Reliable Hardware
A speed dome camera generally consists of a junction box, mechanical unit and camera unit. Each unit is made up of several functional modules or printed circuit boards. For example, power, networking or fiber modules can be found inside the junction box, while the camera unit consists of a lens module and main board. Each unit affects overall performance.

While all speed domes share a strong resemblance, quality is enhanced with attention to detail. Reliability is built on foundations of components, and Actiontop starts with quality control for its video components, said Weingart.

This insistence on using quality components is shared among Asian vendors. "All of our components are sourced from designated suppliers of international brands," said Lora Tsai, Sales Manager at Eyeview Electronics.

Camera Modules
Asian manufacturers, such as Dahua, Eyeview, Hikvision and Merit LILIN, design their own camera modules. The suppliers either outsource the manufacturing process or capitalize on their own manufac?turing abilities.

Higher magnification levels of 22x, 23x, 35x and 36x coupled with auto-focus function are becoming standard. Full firmware and software support are provided for enhanced image stability. "An electronic image stabilizer that digitally adjusts blurring image resulting from external vibrations will be made available this year," Tsai said.

"Speed domes' fast pan-tilt operation require powerful zoom control and proportional focusing capability," said Johnny Chen, PTZ Manager at Merit LILIN. "While maintaining precision and stability, Li-Lin's technology allows fast optical zoom from 1x to 35x within 3.5 seconds and focus adjustment within a second."

PTZ Modules
Stable positional movement depends largely on the motor and belt drive that reside in the PTZ unit. High PTZ speed is engineered with care to reduce the slightest vibration. "Packaged with a nimble 500 degree-per-second pan action, Tiandy's speed domes make sure precision is met," said Francis Jing, Manager of International Department at Tianjin Tiandy Digital Technology.

Self-developed PTZ modules are becoming more available. Although similarity is found in the mechanical design, Dahua, Hikvision, Merit LILIN and Minrray Industry have heeded pronounced technical challenges.

In demanding outdoor environments, heaters and cooling fans reduce the effects of extreme weather, such as snow, wind or heat. However, heating and ventilation in a dome system increases the risk of leaks and condensation. "Replacing electric resistance with heating wires allows the heat to be evenly applied to the mechanical unit without creating hot spots," Wang said. "An electrical safety device is also installed for added protection."

Reducing power consumption helps customers save energy and increase reliability, said Jacy Xia, Marketing Manager at Minrray Industry. "Minrray's PTZ technology allows speed domes to operate with lower watt and automatically consume less electricity in static positions," he said.

Transmission and Cover
Power, video and telemetry connections are routed for data transmission. While high cruising speeds has made integration challenging, customized slip ring mechanisms assure effective transmission, Chen said. In addition, network interface and optical transmitters are now provided for an alternative streaming option and network application.

A dome cover needs careful thought from material to manufacturing processes. "Video quality is affected by almost every aspect of the cover it is outfitted with," Chen said. "Evenly shaped surfaces and coating that reduces reflection and increases resistance to erosion are required."

Lower TCO
In addition to the initial product cost, operation- and maintenance-associated costs should be taken into consideration. "Our prime goal is to reduce installation and recurring costs on top of our cost-efficient models," Wang said.

Customization should also be considered. "Production costs have been minimized and leave less room for further reduction, as our products aim to bring down modification costs for specific applications," Weingart said.

Ease of Installation
Installation should be simple and fast. Tools such as three-axis mounting mechanisms or a set of sockets are provided to smooth an installer's job. "Tiandy's patented magnetic fixing allows tool-free installation and brings the benefit of good anti-vibration and increased product lifespan," Jing said.

System integration should be set up easily. "A test on the serial communication runs automatically to inspect compatible protocols, connects to the controller and reports transmission failure," said Ping Hu, Project Manager at Hikvision Digital Technology.

Configuring networked domes should be made flexible. "Speed domes can be assigned with a programmable address, making changes on virtual addresses easy for future expansion," Hu said.

Operating Software
Designed to fit into a video system, a speed dome should feature a multilingual, intuitive onscreen menu. Other optional features that are becoming standard include built-in motion detection, user-definable privacy zones, preset positions and programmable tours.

Video analytics are developed with automatic PTZ tracking. Vendors such as Dahua and Tiandy have engineered algorithms that differentiate humans from objects and enlarge targets for constant visual surveillance if needed.

Selection Criteria
Manufacturer credibility, product reliability and self-explanatory operating software are primary considerations for a quality speed dome. Technical abilities and after-sale services make sure mainte?nance needs are met and allow for customized applications, Jing said.

Although a full range of features and functions is optimal, high reliability is emphasized. Proven quality under extreme weather conditions and maintaining low malfunction rates are important parameters, Wang said.

Last but not the least is the ease of operation. Tailored software makes full use of the camera's intricate hardware. The powerful PTZ functionality of speed domes requires a simple instruction manual to achieve maximum effectiveness.

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