Combining Alarm Systems with Video Surveillance for Effective Intrusion Detection

By: Randy Bragg, Brownstone Security
www.brownstoneps.com

Alarm systems and video surveillance both have many benefits when used alone, but when combined they act as a more powerful deterrent and detection method of intrusions by unwanted persons and/or other criminal acts.

Traditional alarm systems have evolved over the years from burglar alarms that sounded a bell to attract attention, to alarms that are monitored by 24 hour central alarm stations that can provide assistance when alarms are activated. However, even with central alarm stations there still persist major problems with false alarms. Normal procedures require the central alarm station to call a predetermined phone number to "verify" the alarm. This works well if the client is actually home and OK, as they can answer the phone, and verify it is a false alarm.

However, if the premises are being broken in to, it is highly unlikely the intruder will answer the phone to get caught. If the central alarm station does not get an answer the alarm is still considered unverified (except in very limited cases such as silent alarms in banks). Unverified alarms are a very low priority for law enforcement agencies to the point that in some cases law enforcement does not respond at all to unverified alarms.

So what is the answer? By adding a video surveillance system that is integrated with the alarm system you can ensure that the alarm can be verified. When the alarm system is activated a camera is also activated allowing the dispatcher to verify if there is an actual intrusion on the premises. The dispatcher can then alert the police to the verified criminal act in progress, and track the incident until the police or other authorities arrive.

Combining video surveillance with your alarm system can help to create a safe and secure environment not only against unwanted intrusions, but also to deter other types of liabilities and losses such as inventory shrinkage and personnel liability claims. Considering Walmart lost over $3 billion and Target over $1 billion to these types of liabilities in a 12 month period of time, it may be the time to look into adding or upgrading your current video surveillance system as a way to protect your business.

Copyright © 2009 by Randy Bragg, August 26, 2009

Are there any advantages to a black and white (B&W) security camera?

Color surveillance cameras have come to dominate the security camera market place and in situations involving good lighting (such as daytime viewing or a well-lit department store) color cameras provide excellent images. After all, color security cameras can provide useful information such as color of clothing that a suspect was wearing, color of a get-away car etc. However, the color information is dependent upon sufficient illumination in the visible light portion of the electromagnetic spectrum. In other words, you need good lighting with visible white light to get color video.

Night time viewing situations are a different story. Practically all color security cameras switch over to black & white viewing when the ambient light levels diminish below a certain point. Most modern high-quality color security cameras have built-in circuitry that senses the ambient light levels, and adjusts the camera settings for night time viewing. So even the best color security cameras see only in black & white when it comes to night time viewing.

So what are the advantages to black & white security cameras?

1) Lower cost - Generally, B&W security cameras cost less due to the fact that they are easier/cheaper to manufacture than color cameras. There are exceptions since there are some very high quality B&W security cameras that cost more due to their exceptionally good light gathering ability in low-light conditions. However, as a general observation, most consumer oriented B&W surveillance cameras are lower priced than comparable color surveillance cameras.

2) Brighter images in low-light conditions - On average B&W security cameras produce brighter images in low-light situations. This is not to say that some high quality color cameras won't be brighter than a cheaper B&W camera. You can get a color camera that is brighter than the B&W camera but you will pay more. The image sensor chips (such as the Sony Ex-View CCD) in those high-end color cameras that give a brighter night-vision image are more expensive to manufacture. However, if you compare a color and B&W camera of equal quality, the B&W will be brighter at night, because the color camera requires a special filter (which is imprinted over the sensor) that reduces the amount light reaching the CCD imaging sensor.

3) Higher resolution - A B&W camera will generally have a higher resolution and therefore sharper image compared to a color camera in the same quality/price range. The reasons for this are technical in nature, but in a nutshell the color security camera needs to utilize more of the CCD sensor resources to pick up the three primary colors red/green/blue (RGB) as well as the intensity of light striking it at each pixel sensor, whereas the B&W security camera only sees varying degrees of light intensity (grey scale). Therefore, the CCD sensor in the B&W security camera is fully utilized to making an image and does not have to divert some of it's resources (pixel sensors) towards picking up color information.

So while color security cameras are a great component of a surveillance system for day time situations, there are some advantages to B&W security cameras that should not be overlooked, particularly those involving low-light situations

7 Tips to Select the Best Security Camera

CCTV (closed circuit television) systems are gaining mainstream popularity as a crime-fighting tool. The do-it-yourself (DIY) security camera system is commonplace. Video surveillance can be a powerful tool, but only if the system is designed properly for the particular situation and intended outcomes. Whether you're in the market for a business or home security camera system, choosing the BEST security camera is key to ensuring that high quality video surveillance footage is obtained.

1) Determine Coverage Area and Target Distance - Before buying a security camera do a simple survey of the area that you want to observe with your CCTV system. What particular area(s) are you covering? Depending on the situation you'll need to choose a security camera that will best capture the scene.

Here's where you need to "think like a criminal" and ask yourself what you would do and where you would go if you were trying to rob the place. what areas would you cross?

You'll most likely need multiple cameras and each camera should be chosen to cover a specific area.

First, determine how wide of an area needs to be covered - this is called the field of view. Next, determine the target distance in feet. The target distance is the distance that the subject is expected to be from the security camera.

Security camera placement is based on several factors such as accessability (i.e. can you install the security camera there and get a wire to and from it?) and visibility of the camera (do you want the security camera somewhat hidden or in plain sight to act as a deterrent?), and of course whether the camera will capture the activity in the area. Exposure to the elements is another consideration when determining placement of security cameras.

2) Select Security Camera Focal Length - Once you have determined the target distance and desired field of view, you'll want to calculate the best focal length for each security camera. The best way to do this is to use an online CCTV lens calculator.

Based on the target distance and field of view, the lens calculator will recommend the focal length lens needed to obtain the desired view and magnification of each security camera. This is extremely important in order to obtain high quality video surveillance footage. There is a trade off between field of view and magnification.

3) Choose the Right Camera Type - There are a huge variety of CCTV cameras manufactured today. The right security camera depends on the specific environment that the camera will be placed in (outdoor versus indoor), the desired visibilty of the camera (do you want the camera in plain sight as a deterrent, or somewhat hidden), and the desired aesthetics (does the security camera need to look nice and blend in with the surroundings or does that not matter?).

Here are some common styles of security cameras:

Bullet Cameras: (also known as lipstick cameras) These are small (about the size of a finger) cylindrical shaped cameras that are usually sealed in a weatherproof housing. They are a well hidden camera due to their small size and inconspicuous shape. These fit well under an eve of a house, and can be used indoors or outdoors.

Dome Cameras: These are very commonly seen in malls and department stores where the security camera needs to look nice and blend in with the surroundings so as not to make customers feel uncomfortable. These security cameras also sometimes come with dark tinted glass which makes it difficult for anyone to determine which way the camera is pointed. Many dome cameras are also fitted with vandalism proof lexan plastic domes to prevent damage. There are also dome cameras that come with fortified metal housings and crush proof glass. Dome cameras come in both indoor and outdoor weatherproof versions.

Box Cameras: These are very commonly seen in some shops and in banks were the security camera does not need to be hidden and is used partially as a deterrent. The box shape of the camera is highly visible and also allows for a variety of variable focal length lenses to be used to achieve the desired coverage area and magnification of details. These security cameras are usually restricted to indoor use only since they are not sealed.

4) Choose Camera Resolution - This refers to lines of resolution of the security camera. The more lines of resolution, the more detail that can be seen in the video so you want this to be as high as possible. 350 lines of resolution is fairly low resolution by current standards. 480 lines is very common and fairly good for general use. 525 to 580 lines of resolution is considered high resolution for standard CCTV and will give the best picture quality. There are megapixel cameras and hi-definition security cameras that have much higher resolution. These are on their way to market but are expensive and require more storage space for the increased video information.

5) Night Vision Cameras with good IR lighting - If your security cameras are going to be used for any night time surveillance where the lighting is dim, then you'll most likely want to choose a security camera that has infrared (IR) LEDs that illuminate the area. IR is invisible to the human eye but not to the camera.

6) Wired vs. Wireless Security Camera - Many first time CCTV buyers are attracted to the concept of wireless security cameras due to the 'high tech' appeal and the fact that no video cable is required. However, be aware that wireless cameras are susceptible to interference from other wireless devices such as cordless phones, wireless internet devices etc. that also utilize frequencies in 2.4 Ghz and 5.8 GHz range.

Also, wireless cameras do require a power cord so they aren't completely wireless in that sense. Finally, wireless cameras require a radio transmitter and receiver which add to the cost of the camera. Whenever possible, use a conventional wired security camera instead of a wireless system.

7) Cost Consideration - In general, the old adage "you get what you pay for" applies to a certain extent when buying CCTV equipment. Sure, you can save some money if you shop around, but beware of very cheap security cameras as you're likely to be disappointed with the results. Find a good vendor who is willing to work with you and takes the time to become familiar with your requirements. Don't just settle for the cheapest security camera. Take the time to research various products, talk with a vendor you can trust and then buy CCTV equipment that represents the best performance for the price as it applies to your security needs. The best value option in CCTV equipment is not always the cheapest one, nor the most expensive one.
 

CCTV Glossary

By: Randy Bragg, MBA, MISM
http://brownstoneps.com/vss.aspx
Aperture - Aperture is the area of the camera lens that gathers light. The iris of the CCTV lens controls the size of aperture.

Auto Iris - Auto Iris Lenses adjust for changing light conditions in a camera view. If the sun shines on a camera with an auto iris lens, the lens will adjust the amount of light so the picture remains clear.

CCD Charge Coupled Device is a light sensitive imaging device for almost all cameras. Typical sizes for CCTV cameras - 1/2", 1/3", and 1/4".

C Mount The C Mount is the type of screw-on mounting for CCTV camera lenses. C Mount lenses need an adapter ring when used with CS mount camera (see CS Mount).

Compression Compression techniques are used in Digital CCTV to reduce the file sizes of recorded video images. Typical compression formats used for video are: MJPEG, MPEG-4 & H.264.

CS Mount The CS Mount is the more recent type of mounting for CCTV camera lenses. Designed for 1/2", 1/3" 1/4" CCD cameras, CS-Mount is the more common lens mount used today in CCTV cameras.

Day/Night Camera A camera that is 'Day/Night' means it can capture video in both day and nighttime. In low light conditions, the Sony Day/Night chipset switches from color to black & white at night to enhance the picture quality.

DSP Digital Signal Processing is a technique by which video quality can be improved by adjusting parameters of the video signal.

DVR Digital Video Recorder is when CCTV footage is converted to a digital signal and stored on a PC Hard Disk. This is now the standard CCTV recording practice.

ExView ExView is a Sony Chipset type that offers very good images in both day and night time. Typically, cameras with Ex-View chipset have good Low Light (LUX) levels.

F-stop F-stop is the ratio of focal length to the diameter of the lens. The smaller the F-Stop number, the more light is passed.

Field Of View The view of the camera in relation to the angle of view and distance of the object from the lens.

Frame A frame consists of 2 interlaces fields. 30 frames are created every second.

Frame Rate The quality of a digital surveillance system is often determined by the total frame rate it can record at. The higher the frame rate, the higher the quality of recording and the more real time your CCTV recording will be - real time recording for 1 camera is 30 Frames Per Second (NTSC).

IP Camera An IP Camera is a CCTV camera that can transmit video and audio over a TCP/IP network. An IP Camera can connect to a local network and streams its video over the network to a Network Video Recorder. IP Cameras can come with additional features including Power over Ethernet, wireless LAN connection and Mega Pixel Resolution.

IP Rating Ingress Protection Scale - 2 numbers indicating the protection level of an outside enclosure - e.g. IP68.

IR Cut Filter An IR cut filter is an extra filter inside the camera that moves behind the camera lens when it gets dark. A camera with an IR cut filter will produce very high quality images in low light conditions.

Iris An iris is a device inside a lens which opens and closes as light conditions change which adjusts the amount of light passed through.

JPEG Joint Photographic Experts Group - an image compression technique used for still images.

Lens Mount See CMount or CS Mount.

Luminance Luminance is the brightness of a video signal.

LUX Used to specify how sensitive cameras are to light (measured in lumens/sq meter). For example, a camera with a LUX Level of 0 can see in pitch black. The lower the LUX level the better the camera will see in the dark.

Mega Pixel Resolution Mega pixel resolution refers to video resolutions now achievable using IP Cameras. Unlike analogue cameras, whose resolution is usually limited to around 752 x 582 (0.4 Mega Pixels), a Mega Pixel IP Camera can achieve far greater resolutions such as 1280 x 1024 (1.3 Mega Pixels) or 1600 x 1280 (2 Mega Pixels). This increase in resolution produces far better image quality than a traditional analogue camera could ever achieve.

Motion Detection Motion detection is a recording method for digital surveillance systems. When someone walks in front of a camera, the pixels change and the DVR defines this as motion. The surveillance system will then record these images to the hard disk. This is a popular recording setup as every event recorded is actually motion driven as opposed to a static image if the system was set to record 'round-the-clock'.

MPEG Motion Picture Experts Group - a video compression technique for video images. MPEG-4 has quickly become the Digital CCTV standard recording compression format. MPEG-2 is used for DVD recording quality.

Multiplexer A Multi Screen CCTV device that allows input of 4, 9, 16 etc. cameras and provides a 'Multiplexed' (or split screen) display of those cameras.

Noise Noise is a video signal interference that usually appears as graininess or snow on the picture.

Power over Ethernet (PoE) Power over Ethernet is a method by which power is transmitted over a CAT-5/6 cable. This is often used with the installation of IP Cameras saving time/money by reducing cabling. An IP Device would need to be fitted with a PoE RJ45 port to use this functionality.

Peak to peak Peak to peak is a video signal measurement from the base of the sync pulse to the top of the white level. A full video signal should be one volt.

PTZ Pan Tilt Zoom - a camera which can be controlled via Joystick or DVR and moved up/down, left/right and zoomed in/out.

Quad Splitter A CCTV device used to display 4 cameras on one monitor.

Resolution The number of horizontal lines a system can display. Digital Resolution (e.g. 720 x 576): 720 = number of points in each row that make up the picture 576 = number of rows

RG59 A type of CCTV Coaxial cable used to transmit CCTV camera video signals to a CCTV System.

Sensitivity The sensitivity of a camera is often configured on your digital surveillance system. Motion detection based recording usually relies on the sensitivity of the cameras to trigger recording.

Telemetry Control of PTZ cameras is provided using Telemetry Control. This signal is sent down 'twisted pair' cable or along the same coaxial cable the video signal is being sent down. Typical telemetry signals are RS-485 or RS-422.

Varifocal Lens A CCTV camera lens whose focal length / viewing angle can be manually adjusted to suit the camera view required. Typical Vari Focal lens lengths are: 2.5mm-10mm, 3.5mm-8mm, 5mm-50mm

Video Splitter CCTV device that splits the video signal from a camera (or cameras) so it can be used more than once.

Zoom Lens A zoom lens is a lens which has variable focal lengths. The image can be 'zoomed' in or out whilst the view of the camera remains in focus.