Q What is hardwired video equipment? What are its advantages and disadvantages?
A Hardwired refers to equipment that is directly connected via cable or wire. For example, a hardwired video camera sends a signal through a cable to its destination (VCR, DVR or monitor). The advantage of a hardwired system is that you can usually rely on having a strong, clear signal at your destination given you are using a reasonable high quality cable limited to a reasonable length. The disadvantage of a hardwired system is the need to run cable between your source (camera) and your destination (i.e., VCR or monitor). This can be cumbersome as well as costly in situations where you have to run between walls, streets and buildings. It’s especially difficult to do so in a covert manner.
Q What is the difference between hardwired and wireless?
A The term wireless doesn’t actually mean that the equipment has NO wires at all. Wireless means that the camera is plugged into a wireless video transmitter which sends the signal to it’s corresponding receiver.
Q What is the difference between omni-directional & directional antenna?
A These terms refer to the signal sent from the transmitter antenna. An omni-directional antenna transmits 360 degrees on the horizontal plane & between 30-40 degrees vertically. This antenna is optimal for mobile applications or operations utilizing multiple receivers because its signal is sent in multiple directions at once. However, omni antennas are usually lower gain and therefore will not transmit as far. A directional antenna transmits forward in a linear pattern with a 15-35 degree conical signal depending on the gain of the antenna. Although its signal pattern is narrow, the antenna is high gain and can achieve greater transmission distances. Directional antennas are best suited for stationary point-to-point applications.
Q Can a quad be used with a wireless surveillance system?
A Most Quad splitters do not function properly with wireless equipment. Typically, the processor chip does not obtain enough signal strength from the video output of the receiver and, at this time, there is no way to increase the output gain of a wireless receiver.
Q Can the antenna be extended from the receiving unit?
A It is not recommend extending the antenna from the receiving unit due to the large amount of signal loss that usually occurs. 2.4 GHz is a difficult frequency to contain in a cable due to its tiny wave length. As the length of the cable between the antenna & the receiver becomes greater, and so does the signal loss becomes greater.
Q How does one covert battery usage requirements into hours of operation?
A In order to calculate hours of operation, the nominal capacity of the battery (in Milli-amps) is divided by the total current consumption rate of the items being powered by the battery. Example: An 800mA battery (.8Amp) is being used to power a black and white board camera that consumes 150mA per hour. Divide 800mA by 150mA to yield 5.33 hours of operational power use.
FYI: Peak battery performance diminishes as it reaches the end of the estimated operational cycle. To insure uninterrupted power performance, replace the battery 15-30 minutes prior to end of cycle.
Q What is a VariFocal Lens?
A Vari-focal is a lens that is designed to meet the most challenging jobs by giving the installer the flexibility to adjust between different focal lengths using only one lens. When the situation calls for an odd focal length lens or you are not sure of the correct focal length required for the installation, using a Vari-focal lens is the perfect choice. How many times have you or your installer set-up a job just to be called back because the customer was not satisfied with the field of view of the picture? More than once, most likely. A simple adjustment to the zoom and focus on a Vari-focal lens is all that is needed to rectify the situation on the spot: a less costly and time-consuming prospect than having to order and install a different monofocal lens altogether.
Why use it?
Surveillance effects are maximized since any desired angle of view can be obtained. There is no need to carry several different focal length lenses to an installation job.
Once installed, even if the field of view requirements change, the system can be quickly adjusted by simply changing the focal length setting of the lens.
Q What is HD-SDI?
A HD-SDI is a new technology in CCTV that offers High Definition 720 and 1080P resolution video over standard Coax cabling.
These HD-SDI CCTV products are ideal for upgrading existing analogue CCTV Installations where higher resolution HD images and performance are required.
SDI is the transmitting technology through the 75ohm coaxial cable by serializing the video signal that is not compressed.
The video signal that is transmitting through SDI is a kind of digital signal. Therefore, contrary to the analog signal which is influenced by the deformation of video signal and the distance of transmit, it is possible to transmit the video signal without limitation of distance and deformation of signal through Equalization and Relocking of the video signal at intervals.
Q When should I use Infra-Red Cameras?
A For indoor application where there is no or very low light but you want to be able to view or record. Thus it is often used for warehouses, store rooms, server rooms where the lights are turned off. For outdoor, at car porches, veranda, corridor, passage ways and balconies.
Q How to choose a CCTV Camera?
A Choosing the correct CCTV Camera for your digital surveillance system is very important. The Digital CCTV Camera, together with a CCTV Lens, uses a CCD (Charge Coupled Device) sensor that captures the image and turns it into a signal that is sent to the monitor or surveillance system.
You will need to decide the following when choosing a cctv camera & lens for a digital cctv system:
- The Digital Camera Location : Will the camera be situated Indoors / Outdoors
- The amount or variance of light conditions for the digital cctv camera : Will the camera have to record in low-light conditions such as at night?
- The Field of View required for the camera : How wide or narrow an angle of vision is required
- The Focal Length – How far away objects you wish to record will be from the camera
- Your budget