What's the difference between Hardware Compression and Software Compression?
Hardware Compression:
Both Capturing Video Signal and Compressing Video Signal are done by DSP chipset integrated on DVR Board. It doesn't need the computer's CPU to do this work. It's low cost of CPU and RAM resources. In this system the computer CPU's task focus on answering network request, streaming the video/audio to network and saving recorded data to local hard disk.Software Compression:
The DVR Board only capture video signal but doesn't compress it, it is the computer CPU and RAM to do this compression work. It's high cost of CPU and RAM resources. In this system the computer CPU and RAM are often overloaded. It is easier to crash than hardware compression system.
How do I choose the correct camera for my application?
This in general is a comparatively difficult decision. Many aspects of the installation must be taken into consideration in order to obtain the correct performance that meets your requirements.
A high-resolution camera should be considered where greater detail of scene is required. E.g. Color 460 TVL, Monochrome 570 TVL. Choosing a more sensitive camera will improve reproduction in poorly lit areas. The sensitivity of a camera is indicated by the minimum amount of light in order for the camera to produce a usable picture. e.g. Color 1.0 Lux at F1.2.
A conventional camera produces a pale backdrop when an object is shot against a bright background. BLC (Back Light Compensation) will counter strong light sources retaining picture quality.
Concentrated light sources directed towards the camera (e.g. car head lamps) can be inverted by an optional peak white inverter or an eclipser function. This has the effect of bringing detail to areas and making an object clear, that would otherwise be shadowed.
When can I use a manual iris lens?
A general rule of thumb is only to use a MI lens in an internal application. This is because you are reliant on the electronic circuitry of the camera compensating for light changes in the scene and this is not able to compensate to the same degree as that of an Auto Iris lens.
Why do I have a clear sharp picture during the day and it is out of focus at night?
This is due to the depth of field changing as the light conditions change and can be easily overcome by following set procedures.
How do I connect an Auto Iris lens to a camera?
This is usually performed by a simple plug-in connection to the rear or side of the camera. However you should always refer to the relevant camera handbook.
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.
What size monitor should I be using?
The correct size monitor is dependent on its use e.g. the number of images to be displayed at any given time, the viewing distance and the available space.
What is Video Termination?
This is the end of line resistance of any CCTV system and this should be set to 75 ohm. Should you encounter any double image or ghosting this is more often than not caused by two pieces of equipment in series both having the 75-ohm switch set on. Only the last piece of equipment should be set at 75-ohm.
What type of illumination can I use with color cameras?
Only lighting within the visible wavelength should be used with color cameras. Tungsten Halogen is often the recommended source of lighting.
Can I use I/R Lamps with color cameras?
The answer to this is a definitive NO. Color cameras are typically fitted with an IR cut filter and will not allow IR light in excess of 700Nm to pass resulting in the camera performing poorly in these circumstances.
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 the maximum distance I can run 12vdc when powering a camera?
This is a commonly asked question and there is no simple answer. Some manufacturers may recommend that their cameras can be run over (X) distance with (Y) cable. This however should still be considered as a general guide. Cable conductor size and installation route must also be taken into consideration. If you are unsure, we would recommend that you contact Technical Support for guidance.
What is Digital CCTV?
Digital CCTV, or Digital Closed Circuit Television, is the technology used in modern surveillance systems. Traditional ,VCR, CCTV pictures are sent via cctv cameras to a closed area, e.g. a CCTV Monitor, this type of CCTV is likely to produce lower resolution images and have to be displayed via cabling in the workplace. Modern Digital CCTV Systems can be operated remotely via a pc or mobile phone, can monitor various locations and can be monitored from wherever there is internet or GPRS Access.