1 What is CCTV?

CCTV means “Closed Circuit Television”. CCTV system is a visual surveillance technology designed for monitoring or records the activities in an area for the purpose of safety and protection of property.

2 Why do I need CCTV?

CCTV helps to protect your business and staff; it is a visible deterrent against theft and vandalism. CCTV can also be useful in home security to monitor and protect the drive and gardens. CCTV footage can be invaluable in the identification and prosecution of the perpetrators of crimes.

3 What are the features of a CCTV system?

The principal features are monitoring and recording. CCTV monitoring is the real time viewing of images from CCTV cameras sent to one or more CCTV monitors. CCTV recording is the process of recording and storing of images from CCTV cameras sent to a VCR, Digital Video Recorder (DVR) or Computer.

4 How do I choose the right CCTV?
The choice of a CCTV system will depend on your needs and your budget. You would need to consider the cameras and recording media suitable to your requirements.

5 Will my CCTV camera see in the dark?
Day/Night Cameras and IR Cameras are capable of seeing in the dark at monochrome mode (black & white).

6 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.

7 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.

8 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.

9 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.

10 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).

11 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.

12 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.

13 What are some different monitoring capabilities of cctv camera systems?
CCTV technology has come far in the last couple years, especially with the growing broadband technology. Depending on how much you are willing to spend and what you want it for, cctv camera systems can pretty much be customized to your every need. You can install cameras on the other side of the United States and be able to see what is going on in your warehouse or office with in your own home. You can even have video conference using cctv technology.

14 Is there an installation process?
Most cctv systems are pretty much plug and play cameras and monitoring systems. Some of the more heavy duty systems do need some installation and you may be better off just getting someone to do it.

15 Do I have to buy a monitor and vcr with my cctv system?
Most cctv camera systems require the monitor. If you just want to observe and not record, a recording device is not needed.

16 Should I buy a wireless or wired cctv system?
That all depends on where, why, and for how long you will be using the cameras for. Wired cameras are for more permanent installation. Wireless cctv systems can be moved around all the time and put into different positions. You may also just want to look and see how big of a hassle installation of a wired system would be, you might be better off just getting a wireless system even though your intentions are permanent. Though, you must realize the wireless signal is less reliable.

17 What if I don’t want people to know where all of my cameras are?
Covert camera systems are shown on the site. You can have anything from clock radio camera systems to smoke detector camera systems with an overview of the area.

18 Bright spot smears on monitor
Cameras are designed to view light reflected from the scene being viewed. When you have a bright light source in the picture, it may produce a bright white spot on the monitor and a vertical white line through it. This is a problem especially at night. Solution: Reposition camera to avoid bright light sources in the scene.

19 Bright background, dark foreground
A bright area in the picture causes the iris to close or the imager to reduce gain. This causes the unlit area to appear darker. Solution: Use a camera with backlight compensation or reposition camera to avoid bright background and/or illuminate foreground to even lighting of scene.

20 Picture rolls when switcher changes
Line locked cameras get synchronization from the AC power supply they use. If camera power supplies are out of phase during switching, you will notice a rolling between frames from one camera to another. This can be confusing to the person monitoring the system. It can also create problems for your time lapse recorders. Solution: Power cameras from the same phase on your electrical panel or use cameras that have a phase adjustment control.

21 Picture is snowy or snowy bars roll on screen
The coax cable is picking up electrical, magnetic, or radio interference. This problem is very prevalent when using inexpensive cable. Solution: Re-route cables away from problem area and use only good quality cable.

22 Picture tears horizontally or snowy bars roll
The system is suffering from a ground loop(s). A ground loop is caused when camera and monitor are powered from sources using different grounds with different ground potentials. If a path for current flow (other than the coax) exists, ground loops are possible. A difference of a few millivolts can cause a ground loop. Ground loops are not predictable and may appear or disappear after the system is installed. Solution: Install a ground loop corrector or power all camera from the same source as the monitor.

23 No picture at the monitor ?
An open or short in the cable is the most common cause. Breaks in the center of conductors are caused by excessive pulling or bending, shorts are usually caused by improper connector installation.
Solution: Disconnect the cable at both ends and check with a meter. 1) From center pin to outer connector should read open. If it reads shorted, reinstall the connector. If it still reads shorted, read cable directly. If this fails and cable still reads shorted, replace cable. 2) Short one end (pin to outer), meter from other end, it should read shorted. If it reads open, check the cable directly. If the cable reads open, replace the cable.

24 Monitor has “ghosts”
When a video signal is not properly terminated it reflects back on itself, resulting in secondary images called “ghosts.” Unless you pass the signal onto another video product, the signal needs to be terminated.