Liberty Technologies | Turnkey Technical Solutions

Analogue Cameras:

Analogue cameras have been around for many years and although the technology is very stable, constant improvements are being made all the time.

Analogue Cameras come in 4 basic variants:

Dome Cameras:
These are typically installed indoors and areas where aesthetics could be important. These cameras can come in a number of models and have a number of features. See below explanation of the various features. The advantage to dome cameras is that one does always know where the camera is looking at and thus “what it can see”. Dome cameras either have a “fixed lens” or a “veri-focal lens”. The fixed lens cannot be adjusted and typically would be 4mm (fairly wide range but not much depth). A variable focus lens typically is a 3 to 9mm or 2.8 to 12mm adjustment available. The larger the mm number, the further the camera can be “zoomed” in.

Bullet Cameras:
Generally available in the same features as their dome counterparts, bullet cameras are generally used outdoors and almost always have built in Infrared (IR) illumination. Because they are very directional, it becomes quite easy to work out where there general field of view is. As with Dome cameras, bullet cameras come in either fixed or veri-focal lenses.

“Box” or CS Mount Cameras:
These are what most people understand a CCTV camera to look like. Box cameras have the advantage of fitting different type of lenses especially if the distance from the camera is quite far, a large (22 to 50mm) lens could be fitted. Box cameras don't however have the added advantage of IR built in. This can be overcome, however, if IR illuminators are utilised. Our preference is to avoid box cameras if possible.

Pan/Tilt/Zoom or PTZ:
These usually quite large in size and more often made for outdoor applications where a large area needs to be covered and the ability to zoom in on an object / person is a requirement. As the name suggests, the camera can “Pan” i.e. rotate usually up to 360°, “Tilt” up and down and zoom in and out – the larger models typically delivering up to 36x Zoom capacity. These cameras would usually also have built-in or optionally addable Infrared (IR) illuminators.

Some terminology you may encounter regarding your camera selection would be:

• Wide Dynamic Range (WDR) which refers to the cameras ability to capture clear images of objects surrounded by a strong back light, while still keeping the background visible. This would be used in a variable light environment.

• CCD or CMOS – This is the sensor which captures the image onto the camera and is at the heart of the camera. The 1/3” typically referred to is size of the sensor.

• LUX Level – LUX Levels refer to the lighting conditions the camera can operate in. Here is a chart to help you understand LUX Levels

0.0001 LUX	Poor Starlight	5 LUX	Average street light
0.001 LUX	Normal Starlight	10 LUX	Sunset
0.1 LUX	Normal Moonlight	15 LUX	Good street lighting
0.3 LUX	Full Moonlight	300 LUX	Minimum requirement for easy reading
1 LUX	Twilight	500 LUX	Well lit room
2 LUX	General minimum lighting for security	5000 LUX	Overcast Day

• IR (Infrared) – Most cameras would typically be equipped with IR illumination. This gives a camera the ability to work in near zero lighting conditions. Bear in mind, when a camera switches to “black and white”

• DN – Day / Night camera. This is if a camera either has IR or can work in very low lighting conditions.

• IP65 (or other number) – This refers to the “Ingress Protection” of a camera or device. Typically an “outdoor” product will be rated at IP65. The 6 being dust-proof and the 5 being waterproof to sprays of water. 66 would be heavy jets of water, 67 is partial submersion in water and 68 being permanent submersion in water. Click here to view this handy IP Chart.

• “x”mm lense: Typically “fixed” lenses will have just one number – generally 4 or 6mm. This means the camera lens cannot be adjusted and what you see is what you see. If a lens however has a range (typically 3 to 9mm or 2.8 to 12mm adjustment is available. The larger the mm number, the further the camera can be “zoomed” in.)

• “x” TVL or TV Lines: This refers to both cameras (typically analogue) and monitors resolution ability. A “standard” analogue camera will typically have around 400TVL while a better quality camera will have 800TVL.

• Auto Iris: If a camera has auto-iris, this means it can adjust the amount of light being let in and would typically be used where there are variable lighting conditions which e.g. a petrol station with cars pulling up with headlights or a camera that pointed in the direction of the sunrise / sunset.