FAQs
Black & White (B/W) or Colour?
The trends are with using colour cctv systems these days. The colour cameras provides clearer identification than B/W . But, in a low light condition like in 0.1 lux, you may need B/W cameras because they generally require lower illumination.What parts do I need?
Camera body, lens, mounting bracket, cable, AC Adapter are the basic parts to produce video and many economic mini camera packages come with all of these parts. You may add a CCTV monitor (if you don't use your own TV), quad splitter or switcher to combine more than one camera, Time Lapse VCR, outdoor housing case and other accessories. Or, you may choose wireless systems to avoid cabling. Network based Web Camera Servers are popular for remote surveillance via the Internet and for convenience in LAN or WAN systems.
How many cameras do I need?
You can use quad splitter or 4 channel switcher to combine up to 4 cameras into one monitor or TV. Or, many "observation systems" come with all in one package, including quad or switcher built-in monitor and 4 cameras. If you need only 2 or 3 cameras, a switching system should be enough. If you only need one camera, using a standard TV rather than special monitor will cut expense. You may need a 8 channel switcher or multi-plexer to see more than four cameras on one monitor.Do I need outdoor CCTV camera?
If you want to mount a CCTV camera outdoors you will generally need to use an outdoor housing case, with or without heater and/or blower. The heater and/or blower built-in housing cases generally require separate power supply. Some cameras are made water resistant and don't need separate housing cases. Some of them also have removable sun-visor covers.Do I need infrared CCTV camera to see in total darkness?
Commercial infrared cameras, some of which are also water-resistant for outdoor installation, can see up to 30ft distance in total darkness. If you need to see farther, you may need professional infrared illuminators but they are usually expensive and complicated to install due to its emission of heat. Infrared cameras work as ordinary video camera during daytime. Most colour infrared cameras work as B/W ones at night. Minimum illumination for most B/W cameras these days is 0.1 lux so you will not necessarily need infrared cameras or illuminators if there is some kind of ambient lighting.What angle of view do I need for the lens?
Widely used and recommended angle of view of the lens for surveillance purpose is 72o to 78o Narrower will give you clearer pictures. Wide angles like 92o can cover more area but it may not contain the required detail or may be distorted.Do I need zoom lens?
A manual zoom lens of, for example, 3.5 ~ 8.0mm will allow you to manually adjust angle of view from 3.5mm to 8.0mm. 3.5mm equates to about 90o of diagonal view angle on 1/3 " sensor camera and 8.0mm sees about 38o. Auto zoom lens can be adjusted at the control centre or from your computer.Do I need DC drive auto iris lens?
A little of auto iris functions are built-in in most of cameras included in most observation systems today. But, when you use professional cameras you may need to separate DC drive auto iris, a motorized device to meet the changes of lighting condition of the sun. Generally, auto iris device is not necessary for indoor application with artificial lightings.
Do I need pinhole lens?
A pinhole lens with a tiny opening can be hidden easily in a wall or ceiling or other objects. Many economically priced mini cameras have built-in pinhole lens . A pinhole lens for professional camera is very expensive.What monitoring system do I need: professional CCTV monitor or standard TV?
If you use 1 camera, a simple TV (which has RCA video input) is definitely recommended. Even for more than 1 camera, if you use combiner like quad splitter or switcher, a TV would be fine. But, for special features like slave video output (to be connected to additional monitor), alarm systems or for packaged observation systems, you may need professional CCTV monitors.What type of CCTV monitor do I need: quad screen or single?
Unless it is necessary to see four pictures at the same time on quad split screen, a switching system which shows the pictures one by one (you can control dwelling time) is recommended for its larger image.What size of CCTV monitor do I need?
12" was the popular size during over the years but these days, 14" for colour and 17" for B/W have become very popular. Or, 4" LCD monitor to place on the desk is another choice.What video transmission is required: wireless, coaxial or multiple wire (DIN)?
Wireless systems can be convenient to avoid cabling works, but can be affected by high voltage power lines nearby, unseen razor waves, huge machines like lathe, metal walls etc. Some wireless systems transmit locally up to 300ft and others up to 700ft. Coaxial cable is conventional in this field and proper for professional cameras. It goes up to 450ft without losing the picture quality. Multiple wires like DIN carries not only video but also audio and power. It can be extended up to 250ft. For remote surveillance, you should consider web cameras.Is a power outlet located close to the CCTV camera?
Or, should the power be supplied from the monitoring place?For professional cameras, the power source is better located close to the camera. You may use 12VDC AC adapter if the camera is installed indoors and if the power outlet is within 5ft. If a professional camera is installed outdoors or the power outlet is located far away, you should use 24VAC AC Adapter. For DIN cables, which come with pre-packaged observation systems or mini camera package, the power source can be close to the monitoring site, but the distance from the power source to the camera should be less than 250ft.
Do I need video amplifier?
When you need to send the video image more than 250ft on mini DIN or RCA cable, or 450ft on coaxial cable, you will need to use video amplifier. You may also need a video amplifier when you want to connect one camera to 2 monitors.Do I need time & date generator?
Many observation systems have built-in time & date generator. But, most mini cameras don't have them and you need one if you want the time & date shown on the monitor. Time Lapse VCR usually has built-in time/date generator.Do I need motion detection? alarms?
In many cases, the motion sensors are possible to connect to existing CCTV systems however they are difficult to sight correctly. However, in digital video recording systems, where the motion detectable area can be assigned with software using a computer monitor, motion detection is simple and easy.
Do I need Pan, Tilt and/or Zoom control?
Pan, tilt and Zoom functionality is required in special circumstances and is generally expensive. There are however some systems with built in PTZ which is easy to install, maintain and control.
Do I need to record the pictures?
On conventional Time Lapse VCR or DVR (Digital Video Recorder)?Conventional Time Lapse VCR, even though inconvenient to review the recorded pictures, is surely economical than DVR (Digital Video Recorder). DVR is getting more and more popular for its convenience and picture quality. (Standard home VCRs are not good to run 24 hours a day and some are only for play, not being able to record.)
Do I need computer based observation system?
With a video capture card which converts analog signals to digital ones, you can connect any CCTV video camera to the computer if it has enough capacity to handle the video files. The more common method is to use web cameras which run fast over the Internet or Intranet (LAN or WAN) with small file sizes. Many so-called "PC cameras" uses C-MOS chip instead of CCD chip and also requires separate software.What does CCD stand for?
CCD is an abbreviation for Charge Coupled Device. The CCD is the image sensor of the CCTV camera. The lens focuses reflected light onto the surface of the CCD chip and photo diodes within the chip produce an electrical charge proportional to the amount of light falling onto them.
What does DSP stand for?
DSP stands for Digital Signal Processing. In a Digital Signal Processing CCTV camera digital circuits carry out signal processing as opposed to analogue circuits. The electrical signals which the CCD chip produces are linked to an analogue to digital converter and brightness level reference points are assigned numerical values. The digital signal processor inside the camera processes these values and produces the video signal.
Do I have to use a Regulated Power Supply?
In general the answer is yes. Most manufacturers will recommend the use of such power supplies as standard with their equipment. You should always consult the manufacturer’s specifications prior to the connection of any power supply.
What is an IR cut filter?
Colour CCTV cameras use a filter mounted on top of the CCD chip which is known as an IR cut filter. The colour cameras use this chip as the spectral response of the CCD chip is quite different to that of the human eye. The filter makes the spectral response closer to that which would be perceived by the human eye. The IR cut filter can affect the sensitivity of the camera at night and therefore True Day and Night cameras have been developed which either have no IR cut filter or a motorised IR cut filter which moves out of the way of the CCD chip at night.
What does TVL mean?
In the context of a CCTV camera TVL (TV Lines) refers to the horizontal resolution (the maximum number of vertical lines the camera can resolve) of the CCTV camera.
What do the IP ratings of your cameras mean?
Camera housings come in various shapes and sizes. With regard to the correct IP rating protection, this will range from dust and water ingress. 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
- Protection against dust – no 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.
What do the lens sizes of CCTV cameras mean?
The Cameras we sell have different focal length lenses which are expressed in millimetres. The smaller the number, the wider angle the lens. A 4mm lens is very wide angle (on a 1/3″ CCD Chip, roughly 62 degrees horizontal viewing angle), whilst as we move up to 6mm the angle closes in and the image appears nearer. If you are not sure what focal length you require, you could choose one of our Vari-Focal CCTV cameras.
What are OSD cameras?
OSD (On Screen Display) cameras have a menu system within the camera assembly that can be accessed in order to set functions such as Iris levels, AGC on/off and most features of standard and advanced cameras.
What is the difference between Auto Iris and Direct Drive Lenses?
An Auto Iris lens is one that automatically adjusts its iris for changes in the scene lighting levels. The motor that opens and closes the iris is driven by an Amplifier that processes a small electronic signal changing with the light level.
A Direct Drive ‘DD’ lens does not have this Amplifier and can only operate with a camera fitted with one. A camera specification will indicate the available output options.
Does the ‘f’ stop matter when choosing a lens?
Yes, lenses are usually specified as having a minimum and maximum ‘f’ stop rating; the ‘f’ stop is a measure of how efficiently the lens allows light from the scene, to pass through the lens and onto the camera CCD sensor. The maximum aperture (when the lens is fully open), is the minimum ‘f’ stop number and the minimum aperture, (just before the lens completely closes) is the maximum ‘f’ stop number.
A low minimum ‘f’ stop number means that the lens can pass more light through during dark conditions, which will produce better pictures at night.
A high maximum ‘f’ stop number may be necessary where there is a high level of light or reflection. This will prevent the camera ‘whiting out’.
What is the difference between simplex and duplex multiplexers?
Video multiplexers are designed to allow recording of several cameras onto one recorder.
Simplex
A simplex machine is best suited to applications where recording only is the priority. Simplex machines cannot display multi screen images (i.e. quad, 9 way and 16 way split) while in the record mode.
Duplex
If an operator is monitoring the system (i.e. security guard) then a duplex machine is more suitable. A duplex machine can provide screen splits and user selectable images without affecting what is recorded onto the recorder. Should you use two recorders, it becomes possible to record and playback simultaneously.
What is a ground loop?
An AC current that can be produced in a cable. This is usually caused by parts of the system being fed from different electrical sources resulting in different earth potentials at each end. The result is interference on the signal, usually in the form of dark bands across the monitor and on occasion tearing in the top third of the image.
How can I eliminate ground loop faults?
This can be achieved in a number of ways, the easiest of which is the installation of a Ground Loop Isolation Transformer. "HumBlock" This is best installed at the monitor or recording end of the system.
What are PTZ preset positions?
So what is a preset position for a PTZ camera? Preset positions are a speed dome camera's memorized P/T/Z and focus functionality. This means a user/operator can set the camera to automatically look at a certain area in your CCTV application. Depending on what you are trying to do and what you want to look at, this can be very powerful. It takes a little research and effort to do a walk through and write down points of a target area that at any time needs fast monitoring of activities or environmental conditions. In certain scenes and applications this is a much needed feature and preset positions allow you to adapt the camera to see an area, with an operator handling the camera. This is great, because humans have a large amount of operator error, that may disrupts the ability for the end user to see what is going on. This is due to over panning, tilting and zooming. To set preset positions we recommend two people to configure this. One can be in the field and re-enact the environmental conditions and the other person can figure the field and settings to where the camera will zoom.
The commands you will use will need to be set using a PTZ controller board. For example to set a preset position you would enter this command:::
[PRESET] + nnn + [ENTER} as a result the LCD screen on your PTZ controller will display:: SET PRESET : nn (nn is a variable, when completed you will define the number for the degree needed)
MostPTZ security cameras have the capability of having up to 128 preset postings. That's right! This is more than enough preset positions you can have programmed so your CCTV surveyor can monitor activity a lot better. Again the main reason for using this is to help you manage your video and adapt the camera faster than what a human operator can manually do. There are some professionals in the field that can pan, tilt, and zoom the camera with no problem, however, they are not faster than the camera! We have some manuals listed on our site, where you can download our manuals and follow along how to operate, set, and delete preset positions.
The Importance of Good Connections.
Reliable video signal continuity through a CCTV system is paramount to picture performance and durability. Making good connections is just as critical as choosing the right products and has a significant effect on the long term operation of a CCTV system.
On it's travels from the camera to the monitor the analogue video signal has to pass through a number of seperate pieces of equipment such as switchers, VCR's multiplexers and so on.
Each Piece of equipment requires a video input, and usually a video output or loop through, to pass the signal onto the next piece of equipment. At each of these points it is usually necessary to terminate the coax cable with a male BNC in order to make the connection.
Often there may be as many as 6 or 8 BNC connectors between the camera and the monitor, if the BNC connectors are made poorly the chances of a clean video signal drop proportionately.
These are some of the faults commonly found with BNC connections;
Shield Short, where strand of copper braiding is touching the certer core. Usually as a result of incorrect stripping.
Short Core, where the core fails to make solid connection with the pin, or the pin is not proud enough within the connector.
Weak Crimp, often as a result of the wrong tool (such as pliers) or a worn crimping tool being used on the pin or ferule. The connection may seem OK to look at but cold weaken through strain.
The different types of BNC connectors on the market have their own advantages and disadvantages but the same fundamentals always apply;
- Always use the correct tools for stripping and crimping
- Always use the correct 75 ohm BNC on the correct grade of 75 ohm coax cable
- Follow the connector manufacturer's instructions and strip the coax to the specified lengths
- Use strain relief boots to for added strength and security