If you see Greek when reading CCTV specifications this simple guide to Understanding CCTV Cameras may just be what the eye doctor ordered. There are many aspects of a security camera to consider and, short of buying or borrowing several models for an initial field test, your best option is to arm yourself with as much information as possible before plunging into the shopping cart and clicking to submit. In this blog we’ll take a basic look at all the specifications for an IR Enabled (night vision) High Definition Digital Camera. Visit Ravica for this and other surveillance cameras for your daylight and lowlight monitoring needs.
NOTE: Before you buy an IR enabled camera for surveillance you should understand night vision (low light imaging) optics, whether in the form of goggles, scopes or cameras require and amplify some presence of light to produce an image. This explains the illumination specification, which will be covered in greater detail later on.
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IR Enabled High Definition Digital Camera
A Breakdown of Specifications for the CCTV – IR Enabled High Definition Digital Camera (HD-DC)
Image Sensor:
- IR range of 20 meters
This is the distance at which subjects can be seen clearly – in this case 20 meters or about 65 feet - 1/3” CMOS (Complimentary Metal-Oxide Semiconductor)
A CMOS is an image sensor that converts light to electrons. Due to their makeup energy consumption is very low. 1/3” simply designates the size of the sensor.
You can learn more about CMOS and its counterpart, the Charge-Coupled Device (CCD), at HowStuffWorks. - Auto White Balance
Light monitoring feature that enables camera to adjust color to maintain white areas - 640 pixels per line, with 625 per frame (interlaced)
Interlacing is a bandwidth saving technique, which doubles the perceived frame rate introduced with the signal.
Picture Elements:
- 640 (H) x 480 (V)
320 (H) x 240 (V)
Picture Elements represent the number of pixels available on screen horizontally and vertically. It helps to think in terms of your personalized computer screen resolution, which you may have set to 800 x 600 or 1024 x 768. The HD-DC has a resolution of 640 (Horizontal) x 480 (Vertical).
Illumination:
- 0.5 Lux (Color), 0 Lux (Black & White)
The amount of light present is defined by LUX (Lumens per Square Meter). One LUX is a candle light volume at a distance of one meter. Unlike black and white, color requires more light, which explains the variation of 0.5 LUX to 0 LUX. As you can see in the broad range of light events below this is an excellent range for low light conditions, particularly from deep twilight to quarter moon.Full daylight; 10,000 LUX .
Very dark day: 100 LUX
Twilight: 10 LUX
Deep twilight: 1 LUX
Full moon: 0.1 LUX
Quarter moon; 0.01 LUX
Using this example can help you gauge what type of illumination is required for surveillance at designated monitoring hours.
S/N Ratio:
- < 48dB
S/N Ratio is the ratio of signal power to noise power expressed in decibels (dB). 48dB is a good-very good rating for CCTV cameras.
CODEC:
- MJPEG
MJPG or Motion JPG is a video format in which each digital video frame is compressed separately as a JPG image. This form of Codec is advantageous as it tolerates a rapid succession of motion with little to no loss of camera image quality.
Power:
- Powered by securityProbe 5ESV or Door Control Unit
The IR-HDDC is not independently powered, which minimizes cables and allows for easier installation.
Lens Type:
- Fixed
Lens has a fixed focus
Focal length:
- 3.6mm
3.6 mm is a short focal length for a wide angle of view. A 16 mm focal length would be used for a narrow angle of view.
Surveillance Cameras Demystified
With CCTV specifications demystified you now have the knowledge to confidently shop for a surveillance camera. Check out Ravica for surveillance and all your other monitoring needs.