Security, surveillance camera: How to choose?


How to install Wired Camera
For a wired system, you need to connect the camera to your display/recording device (TV, VCR etc.) by means of a RCA cable (or a coax cable). Depending on the model you order, there are 3 cables with RCA connectors coming from the camera: the DC power wire, and the other two for video and audio respectively. Plug the video and the audio connectors to the RCA video-in and audio-in jacks at the back of your TV or VCR. Then connect the power wire to the included power supply, which then be connected to the AC power source. If AC power is not available at the location where you want to install the camera, you may use the included battery box or connector to connect the camera to a 9V battery. For longer battery life, you may connect the camera to a high capacity Sealed Lead Acid rechargeable battery - more information in Resources Page. Back to the top

How Wireless Camera Works
For a wireless system, connection between the camera and the display device is done by a transmitter and a receiver. The wireless system consists of a camera, a transmitter and a receiver. Though our pinhole camera is so small, we build in a video/audio transmitter inside some of our models of pinhole camera! The transmitter sends the video and audio signals from 300 feet to many miles away (depending on which camera model) to a wireless receiver. The receiver can be easily connected to video/audio input jacks of a TV, monitor, VCR, DVR or even computer. Your may view or record the video live as you wish. Miniature wireless camera can be hidden inside an object like a clock radio, air filter or CD player etc. Most wireless systems in the market do not include audio capability. There are some models of our wireless camera providing both video and audio transmission. Please make sure you choose the right product. In all the standard TV, VCR, DVR or monitor, you'll find an RCA video-input along with an audio-input usually located at the rear of the unit. Back to the top

What is Camera Resolution meant?
Resolution is a measurement unit of the camera's clarity. A cameras resolution is determined by the number of horizontal video lines (320~600 lines) that the camera needs in order to reproduce the desired image. The higher the resolution number, the sharper the image will be. Back to the top

LUX--How it affects picture quality
The illumination factor LUX (1/10 of a foot candle) is a standardized unit to measure a camera's sensitivity to light. The lower the number, the less light it will need to reproduce a clear image. A camera with a LUX of 1 means it can see an image during early evening hours or just before dusk. A camera with 0.5 LUX has the ability to see an image in a dimly lit corridor. A 40W fluorescent lamp will provide sufficient indoor light for a camera with 2 LUX. With the help of infrared light, camera can work with 0 LUX, i.e., under total darkness, even better than the human eyes! Back to the top

What does it mean by LOS (line of sight)
LOS refers to the distance between the AV transmitter and the receiver in open space (line of sight). There are a number of factors that may adversely affect the transmission range in actual environment. If there are walls, partitions or other obstacles between the transmitter and the receiver, the effective transmission distance will be much shorter. Wireless signal can penetrate through some solid obstructions such as wood, tree, glass, non steel-embedded wall, partitions but the signal will be attenuated depending on the number, thickness and the type of obstructions transmitting through. For example, a steel-embedded concrete wall will attenuate the signal much more than a wooden partition. A standard construction wall can reduce the transmission distance by as much as 80%. Strong radio frequency of similar range in the area and/or poor weather will also adversely affect the operating range. In order to improve signal reception, try to place the antennas of the transmitter/receiver in a higher position whenever possible. Reallocating the transmitter/receiver to different locations and/or changing the channel may also get a better result. Using a high-gain antenna for the transmitter and/or the receiver will definitely improve the signal transmission and reception if the operating environment is open space.

For long distance transmission, it is not enough to be able to see the other side but the Fresnel zone needs to be clear of any obstructions, or at least that 60% of the first Fresnel Zone must be clear of obstacles. Back to the top

What are CCD and CMOS image sensors? What are the impacts on choosing the camera?
Both CCD (Charge coupled device) or CMOS (Complimentary Metal-Oxide Semiconductor) image sensors are electronic devices that use a variety of technologies to transform an image (light pattern) into an electric image (electronic charge pattern). In the process of reading the value in the image, CCD sensors create high-quality, low-noise images. While CMOS sensors, traditionally, are more susceptible to noise.

In the conversion and reading processes, CCDs consume lots of electric power. CMOSs operate on lower voltage and therefore consume much less power. The difference in consumption is as much as 100 times. Accordingly, CMOSs have much longer battery life than CCDs.

CCD sensors have been in mass production for a long period of time and therefore a more mature product than CMOS sensors. CCD sensors tend to produce higher quality and more pixels. As a result, the images produced by CCD sensors are much better than those from CMOS sensors.

The third major difference between these two sensors is that the manufacturing costs of CMOS is much less expensive than CCD.

Based on these differences, you can see that CCDs tend to be used in cameras that focus on high-quality images. CMOS sensors tend to have lower quality, lower resolution and lower sensitivity. There is a trade-off between higher image quality but higher power consumption (CCD) compared with lower image quality but longer power consumption (CMOS). Back to the top

How to choose a camera for security purpose?
There are lots of security camera in the market. Which one is suitable for you? These cameras may come with or without audio capability. Make sure you choose the correct one to suit your needs. Security camera basically includes (1) Pinhole Camera. Some are as small as a sugar cube with lens opening of 1 mm. It can be hidden behind any hole larger than 1 mm. (2) Board Camera: A small PC board with built-in mini camera. Suitable for hiding into many objects. (3) Dome Camera: A mini camera is built inside a dome-size plastic obscure protector. Suitable for installation on the ceiling or wall. (4) Standard Surveillance Camera: Visible security camera installed indoor or outdoor to scare away unwanted visitors; (5) Water-resistant Security Camera: Standard surveillance camera with water-resistant protective case. Suitable for outdoor installation. (6) Water-proof Hidden Camera: A small pinhole or mini camera with water-proof case so that it may be put beneath the water, for example, inside a fish tank.

The technology in these models is basically same for different models, except that the camera may consist of either a CMOS or CCD image sensor, and the product size is also different for different purpose. Back to the top

Should I buy a color or a B/W camera?
If you use the camera in an environment where the light condition is very low, it is recommended that you should buy a B/W camera. If a color camera is used under low light condition, the video obtained will be near B/W anyway. Buy a color camera for a better view if the light condition is fair. Back to the top

Should I install a Night Vision Camera?
Night Vision Projector is a device sending out invisible infrared light to compensate the light for the camera. Usually, the light requirement for B/W camera is very low. Some light coming from a dim light bulb or a corridor lamp is already sufficient. If you want to take video from a location where the light is very dim or no light at all, then you need to install a camera with built-in infrared lights. If a color camera is used under low light condition (even with infrared night vision device embedded), the video obtained will be in black and white only. Back to the top

Should I buy a Wired Camera or a Wireless Camera?
The advantages of wireless camera are that (a) it is convenient to be installed in those locations where wiring is difficult, if not impossible; (b) it can be moved to different locations easily, as often as you like; (c) it can be hidden inside a moving object like inside your cloth, cap, briefcase or carrying bag etc. The disadvantages are: (a) video stream may be disturbed or influenced by other moving objects or other strong radio frequencies. A wired camera is more stable in this respect. (b) video/audio transmission is limited within the prescribed transmission range. These disadvantages will not occur to a wired camera.

To overcome the disadvantages of wireless camera, you may:
(a) Buy those wireless models operating with less commonly used frequency band; (b) If the distance between the wireless camera and the receiver is long, or there are walls, metallic or steel obstacles in the transmission path, buy a wireless model with higher transmission power, that is, a transmitter with longer transmission distance; (c) Using a high gain antenna for the transmitter and/or the receiver will definitely improve signal transmission/reception. (d) Place the antennas in a high location so that they can "see" each other.

Overall, the video/audio signals from a wired camera are more stable than a wireless camera. Back to the top

What is Video Standard?
Different areas of the world use different video standards. North America uses NTSC, Europe uses PAL and SECAM, South America uses PAL-M, PAL-N, PAL and NTSC. Almost every area of the world has a mixture of video standards. If your TV/recorder/camcorder support multi-systems, you can use either PAL or NTSC camera. With a multi-system video recorder, you expect an PAL tape to be reproduced as a standard PAL signal, and the same machine if fed with a NTSC tape will reproduce it as a standard NTSC signal. A multi-system recorder can also be expected to make a perfectly normal PAL recording of an PAL input signal, and a perfectly normal NTSC recording of a NTSC input signal.

NTSC and PAL standard are not interchangeable. Video input from a PAL color camera on a NTSC only TV will be displayed in B/W only, not in color. Back to the top

What is PAL, NTSC and SECAM?
NTSC (National Television Standards Committee) is a standard used in North America and Japan. It has the ability to display up to 525 lines of resolution. PAL (Phase Alternating Line), a standard used almost everywhere else in the world, has the ability to display 625 lines of resolution. SECAM (Sequential Color Memory) is used sparingly around the world and can be found in France, parts of Greece, Eastern Europe, Russia, Africa and a few other parts of the world. However, any SECAM country can display PAL tapes in full color, but not all PAL countries can display all SECAM tapes in color. Only if they are true SECAM and not MESECAM can those VCR's display SECAM. Back to the top

Note: Unless it is indicated in the product description that the camera is only available for certain video format, or you specify a video standard in your order, we will ship camera according to the common video format currently used in your country. For example, NTSC camera for orders from United States and Canada. For orders from U.K., we will ship PAL standard camera. Back to the top

How to choose a suitable lens for the camera?
Lens with fixed focal length
Choosing a suitable lens for your security camera, you need first to determine how far you want to monitor the scene. A 4mm lens will give a 72 degree visual angle of view for a person's face detail in about 30 feet. This will be adequate for most home or small office surveillance system. Based on this calculation, a 8mm lens will give a 40 degree visual angle and zoom in 2 times of the view in the same distance. Accordingly, a 16mm lens will give a 20 degree visual angle and zoom in about 4 times of the view in the same distance.

Varifocal lens
If you need to change the monitoring distance at times, you may choose a varifocal lens instead of lens with fixed focal length. With a few simple adjustments of the lens, you will be able to zoom in and zoom out and focus a clear picture of the scene. There are various focal ranges offered by the varifocal lens, i.e. 3~8mm, 8~15mm etc.

Auto iris lens
An auto iris lens is a lens that automatically adjusts the lens aperture based on the strength of the incoming light source. If the security camera is installed in the office, you probably don't need an auto iris lens because the light source is stable. If the camera is installed outdoor, you may need an auto iris lens because the light source may change through the day. Back to the top

Please visit Product Summary to see which product is suitable to you.

Useful information can be found in the Resources Page


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