Frequently Asked Questions

22 Things you need to know about security systems

1.What is CCTV & Why is there a need for CCTV?

CCTV is the abbreviation for Closed Circuit Television. It is a visual surveillance technology
system designed to monitor the desired surrounding environment and its activities. In recent
years, the role of CCTV has grown to unprecedented levels. Originally used to deter crime and
‘anti-social behavior’ such as minor offenses like littering, urinating in public and etc, CCTV now
plays a more important role, assisting the police and security organizations in their investigations.
Britain is currently the leading nation in implementing CCTV, most British towns and cities are
moving to CCTV surveillance in public areas, housing estates, car parks and public facilities.
Other countries are quickly following. North America, Australia and some European countries are
installing the cameras in urban environments which a few years ago would most likely have
rejected the technology
In Singapore, an extensive round-the-clock CCTV surveillance system covers majority of the
highways and roads island wide, providing 24 hours visual surveillance on traffic situations. With
the system, authorities are able to response faster to traffic situations. In recent years, there is a
vast increase in demand for CCTV applications. Thousands of cameras are installed island wide.
They can be found in various places such as shopping malls, boutiques, bus terminals, MRT
stations, underpasses, Automatic Teller Machines ATM, sensitive government buildings, private
estates and even extending its application to red-light districts, in an attempt to monitor and deter
illegal activities.
CCTV is fast becoming an integral plan for crime control policies and social behaviour control
theory in an effort to maintain ethnical public behaviour and public order. It has become an icon
for security and its presence is guaranteed to generate a sense of security and welcomed by
many.

2. Can CCTV prevent crime?

CCTV acts as deterrence rather than prevention to crime. CCTV deters ‘opportunistic’ crime,
where people take advantage of a situation on the spur of the moment.
The cameras are also creating a vastly increased rate of conviction after crimes are detected.
Virtually everyone caught committing an offense on camera pleads guilty nowadays. Once people
know they have been videotaped, they admit the offense immediately.

3. Will the Camera’s work anywhere in the World?

The output of CCTV cameras is composite video. U.S, Japan and Canada uses NTSC system
whereas most Asia and European countries uses PAL system 

4. What is NTSC and PAL system? 

NTSC stands for National Television Standards Committee. It is the colour video signal television 

standard: 525 lines, 60Hz PAL stands for Phase Alternate Line. It is the colour video signal television standard: 625 lines,50Hz

5. Which countries using NTSC and PAL system? 

 

Albania PAL GermanyEast SECAM/PAL Morocco SECAM Trinidad NTSC
Argentina PAL-N Gibraltar PAL Netherlands PAL Tunisia SECAM
Australia PAL Greece PAL New
Zealand
PAL Turkey PAL
Austria PAL Hong Kong PAL North Korea SECAM United
Arab
Emirates
PAL
Azores(Portugal) PAL Hungary PAL Norway PAL United
Kingdom
PAL
Bahamas NTSC Iceland PAL Pakistan PAL Uruguay PAL
Bahrain PAL India PAL Paraguay PAL USA NTSC
Barbados NTSC Indonesia PAL Peru NTSC Venezuela NTSC
Belgium PAL Iran SECAM Philipines NTSC Yugoslavia PAL
Bermuda NTSC Ireland PAL Poland PAL Zimbabwe PAL
Brazil PAL-M Israel PAL Portugal PAL    
Bulgaria SECAM Italy PAL Romania PAL    
Canada NTSC Jamaica SECAM Russia SECAM    
Canary Is PAL Japan NTSC Saudi
Arabia
SECAM    
China PAL Jordan PAL Seychelles PAL    
Colombia NTSC Kenya PAL Singapore PAL    
Cyprus PAL Korea NTSC South
Africa
PAL    
Czechsolvakia
(N.A)
SECAM Luxembourg PAL South
Korea
NTSC    
Denmark PAL Madeira PAL Spain PAL    
Egypt SECAM Madagascar SECAM Sri Lanka PAL    
Faroe Islands
(DK)
PAL Malaysia PAL Sweden PAL    
Finland PAL Malta PAL Switzerland PAL    
France SECAM Mauritius SECAM Tahiti SECAM    
Gambia PAL Mexico NTSC Taiwan NTSC    
Germany PAL Monaco SECAM/PAL Thailand PAL    

 

6. How to choose a suitable CCTV camera for your needs? 
Choosing the correct CCTV Camera that fits your digital surveillance requirements is very
important. Below is a simplified set of guidelines when choosing the correct CCTV camera for
you application.
a) Location: Indoor or outdoor application
b) Requirement for day and night surveillance
c) The angle of view requirement. Wide angle coverage or a narrow field of view is
required.
d) Budget

7. How does focal length affect angle of view? 

Focal length is measured in mm. A short focal length (e.g. 3.6mm) represents a wide angle of
view while a long focal length (16mm) represents a narrow angle of view.

8. What is Auto and Manual Iris? 

Auto Iris lenses are lenses that are able to change the size of their iris in accordance to its
surrounding light condition. When the camera mechanism detect that there is insufficient light, the
lens will automatically enlarge its iris to accommodate more light in so it could focus properly and
produce images that are not too bright or too dark to see. It will do the reverse when it’s too bright.
For outdoor applications, where the light conditions are constantly changing, auto iris lenses are
needed.
For indoor applications, where light conditions are constant most of the time, a manual Iris lens
would be sufficient for the application. Manual iris lenses provide an effective solution for
applications where the surrounding environment and its lighting conditions are relatively stable. It
gives the best performance when used with cameras that are equipped with electronic shutters.

9. What is the difference between video driver and a DC driver in an auto iris lens? 

Auto iris lenses need a driving circuit to control and operate a motor to adjust the aperture range
in accordance to varying light conditions. The driving circuit can be placed on either the camera
lens or inside the camera itself.
For video driver function, the control circuit is found on the camera lens. DC driver function
camera has the control circuit built-in in the camera itself.
Depending on the type of lens and camera you are using, you should always set it to the correct
setting in order for the auto iris function to operate correctly

10. What is Day and Night Camera?

Day and night cameras are cameras that are able to provide video surveillance even at low levels
of illumination. A day and night camera displays a full colour image during the daytime but
produces monochrome (Black and white) video images at times when the lighting is poor. The
camera has a device that is sensitive to the surrounding light conditions and switches the camera
between colour and black & white modes automatically. It is designed to increase its light
sensitivity in poor lighting conditions and at the same time reduce noise level in the images.
However, the day and night camera will fail if the illumination (Lux) level is too low.

11. What is IR camera?

IR is the abbreviation for Infrared. IR cameras have image sensors that are designed to sense
and process infrared light emitted from IR LEDs. Similar to Day & Night cameras, IR cameras
turned to monochrome mode when illumination falls below a certain Lux. An IR camera differs
from a Day & Night camera in which an IR camera is able to capture video images in absolute
darkness with the help of infrared light source.

12. What is C and CS mounts?

It refers to the 2 different standards of CCTV camera lens mount. The difference between the two
is the distance between the lens and the image sensor. C mount: 17.5mm, CS mount: 12.5mm.
Cameras and lenses nowadays are generally CS mount rather than C mount. With CS mount
cameras, both types of lenses can be used. However, the C mount lens requires an additional
5mm ring to be fitted between the camera and lens to achieve a focused image. With C mount
cameras it is not possible to use CS mount lenses as it is not physically possible to mount the
lens close enough to the image sense to achieve a focused image.

13. What camera housing to use in outdoors and at what IP rating?

Camera housings are of various shape and sizes. Different housing comes with different UP
rating, from dust proof to all weather rating. This system is governed by a number of European
and British standards
IP55:
• Protected against dust – limited ingress
• Protection against low pressure jets of water from all directions – limited ingress permitted
IP65: 
• Protected against dust – limited ingress
• Protection against low pressure jets of water from all directions – limited ingress permitted
• Protection against high pressure water from all directions – limited ingress permitted

14. What is CCTV DVR?
DVR is abbreviation for Digital Video Recorder, it main function is to compress images recorded
from the cameras into a particular image compression format and store them.

15. What is the difference between a PC-based DVR and an Embedded DVR?

A PC-based digital video recorder is basically a personal computer that has been modified with
hardware and software to work as a DVR. An embedded digital video recorder is a video
recording machine that has been manufactured specifically to record video input from CCTV
cameras. In embedded DVRs there is typically one circuit board with software burned into its
processor chip.
There used to be significant differences in features between the PC-based and the embedded
machines. But with recent advancements in the embedded DVR technologies the differences are
becoming less. The advantage of an embedded digital video recorder is that they are extremely
stable and reliable as they consist of fewer circuitry parts. The software is often written in basic
machine code or Linux code which tends to be more stable.
The advantages of the PC-based digital video recorders is that they are easier to interact with
because you use the on-screen menus and a mouse (as opposed to embedded which you
interact with more like a VCR – via buttons). And you tend to have more features and options on
the PC-based machines.

16. What features should I look for in a CCTV DVR? 

All DVRs are different. There are various factors to consider when purchasing a DVR besides
price comparison. The basic and most important factors to consider are
i) Number of cameras supported, i.e. number of video inputs
ii) Recording at how many frames per second (fps)
iii) Compression technology used
iv) Hard disk space, number of hard disk it can support
v) Network connection / remote viewing capability
vi) Motion detection or scheduling recording functions
vii) Video backup means, by USB, CD, DVD or other means.
viii) Easy and comprehensive search capabilities

17. What is the term frames per second (fps)? 

Frames per second (fps) relates to how many pictures the DVR can record in a second. Real time
recording is about 30 fps. To calculate the fps per camera, take the total fps that the system could
offer and divide it by the number of video inputs. For example, a 100 fps DVR with 4 video inputs
would give u 100/4, 25fps per camera.

18. What is image compression and what are the types of compression formats used? 

CCTV DVR converts analog images to digital and save them in hard disk. Image compression
plays an important role of improving transmission as well as reducing storage size. There are
various formats of image compression in the market. Among which, JPEG and MPEG format of
compression are the most widely used formats in the market currently. The major difference
between JPEG and MPEG is in compression techniques. JPEG processes images by
compressing one by one still pictures but MJPEG compresses images sequence by sequence.
JPEG compression method can be divided into JPEG, M-JPEG, wavelet and etc.
MPEG compression method can be divided into H.263, MPEG, MPEG-II and MPEG-IV.

19. Do I need 30 frames per second (fps) recording on all security cameras? 

CCTV surveillance systems are generally intended to capture images and not to make movie
quality videos. Recording rates of as low as 1 or 2 frames will be sufficient to capture critical
moments for example, a criminal act in progress. Even at low frame rates, recording on motion,
the compressed video files produced per day are huge in size. Therefore, it is not advisable to set
all cameras to be recording at a high frames per second rate.

20. How many days/weeks of recording can I store?

This depends on the size of your hard drive, the number of cameras, which recording mode (on
motion, on alarm, continuously, etc.), what type of video compression you are using, quality of
resolution used. Please contact our technical support directly for assistance on the calculation.

21. What is the difference between a simplex DVR and a duplex DVR? 

A simplex DVR only performs one task at a time. The DVR cannot playback recorded videos
when it is recording, it can only do so when the recording is stopped.
A duplex DVR is able to playback recorded footages without having to stop recording. Recording
is uninterrupted and taking place concurrently as you playback the recorded videos.

22. What is the maximum length I can pull my cameras away from the DVR? 

Using RG59 Coaxial cable, the maximum distance is approx 600 feet away from the DVR and up
to 1,000 feet using RG6 Coax. For longer distances, a video amplifier should be used.