Choosing The Right DVR?

Until 2009 you could simply evaluate the recognition standard of a CCTV system based on what percentage of the screen a person filled (see previous section). But with the latest standard from the Home Office things are slightly more complicated. These percentages are based on the PAL televisions standard which was used for most systems. Now, however, there are a number of recording resolution formats available and the above sizes depend upon the quality of each format. The following table based on the Home Office Operational Requirements Manual for CCTV – page 10 outlines some of the most popular formats.

So if you are using the PAL system and wish to Identify an Unknown Person they need to be 100% of screen height and to Recognise a Known Person then must be a minimum of 50% of the height of the screen etc. However if you have a recorder that produces pictures in 4CIF or D1, because the resolution is better than PAL to Identify An Unknown Person they only need to be 70% of screen height and to Recognise a Known Person they must be a minimum of 35% of the height of the screen.

The problem comes if you purchase a unit that only records in 2CIF or CIF. Now a person has to be 70% height of screen before they are recognisable and it is almost impossible to meet the Identify standard as they have to fill 139% of the screen. This also means that the area you can cover if attempting to recognise a person drops from a screen width (the width of the area viewed on the screen at the point that the target person is standing) drops from 4.5m to 3.2m.

The Home Office Operational Requirements Manual for CCTV – page 14 also states that while recording one picture per second per camera is adequate where there is little activity, 6 to 12 pictures per second per camera should be recorded where there is busy activity such as doorways.

We recommend that you purchase a Digital Video Recorder that can record in D1/C4 format at 6 pictures per second for the length of time you wish to keep the recordings.

www.truvision.co.uk

CCTV Resolution Explained.

CCTV Resolution can be very confusing because there are several different applications of it. In this article you will find our best attempt to explain the differences in as much of a non-technical manner as possible.

First to identify a few terms to help guide us. With the advent of high definition TV a new term has developed referring to the old TV format has standard definition. That terminology has seemed to creep into video security as well. A camera could be referred to has standard definition which basically means it is not a megapixel camera. However a camera may be called a High Resolution camera but it is still a standard definition camera. Now an analog camera or IP camera for that matter could be 380 TV lines of resolution and it would be called a low res camera. However, a camera with 540 TV lines would be called a high res camera. However they could both be considered standard definition cameras because they are not megapixel cameras or HDTV cameras. We will explain more about megapixel and IP in a moment.

CCTV Resolution...continued

In CCTV Video Security Systems the main differences of CCTV resolution are capture, display and storage resolution.

Capture or Camera resolutions for analog cameras

When reading a security camera specification sheet, you will see two sets of numbers rating the sensor of the camera. One lists the number of pixels (768 H X 494 V) for the sensor and the other rates the horizontal resolution (TVL) of the camera.

Effective pixels = 768 (Horizontal) X 494 (Vertical) Horizontal resolution = 540 TV lines

The difference between the two is pixel aspect ratio and picture aspect ratio. The pixel aspect ratio has to do with the actual number of pixels that sensor is able to capture. The picture aspect ratio is based on what the NTSC standard for analog signals (composite video) has been designed to process. The numbers are different but using the math behind it you can calculate how the two relate. We will avoid the math for this discussion.

Since analog standard definition security cameras do not have square pixels there are two types of picture aspect ratio. There is storage aspect ratio and display aspect ratio.

Storage Aspect Ratio

The storage aspect ratio is the digital size of the image as it is stored on digital media. For instance the highest stored resolution using composite video (which is what comes from an analog camera) is 720x480. That is the same as a standard definition DVD movie.

When storing video on an analog security DVR you have several resolution options. The typical settings available for storage are CIF, 2CIF and 4CIF.

CIF	352 x 240
2CIF	704 x 240
4CIF	704 x 480

Display Aspect Ratio

The display aspect ratio can only be displayed as what is referred to as a 4:3 aspect ratio which is the NTSC standard. This limits the number of lines of data that can actually be displayed. This explains why a 768 horizontal sensor when displayed on a 4:3 aspect monitor will result in only 540 TV lines of resolution. (note: a standard definition movie on a dvd could be in 4:3 or 16:9 format but the pixel size would still be 720x480 for storage purposes.)

Newer standards for TV have introduced High Definition TV with an aspect ration of 16:9 which allows for a greater number of lines of resolution to be displayed. Newer technology of cameras are now able to capture higher resolutions which will now allow for storing and displaying these higher resolutions.

Standard Resolution IP Cameras

Standard resolution IP cameras can produce the same resolutions options as shown above for DVR storage and the video data can be stored on a HDD using any PC that the camera software is installed on. They can usually also do full D1 resolution which is 720 x 480. Standard resolution IP Cameras can also capture 30fps. Typically they are setup to run at lower resolutions and frame rates to help with bandwidth and storage of the data.

Megapixel resolution IP Cameras

Just a note about megapixel IP cameras. Megapixel cameras can capture video at much higher resolutions but are not necessarily the same as High Definition as in HDTV. HDTV has a very specific set of resolutions available. 720p HDTV is 1280 x 720 and 1080p HDTV is 1920 x 1080. HDTV also operates at 30fps.

A megapixel camera that is 1.3 megapixels has a resolution of 1280 x 1024. From there the megapixels go up. 2, 3, 5, and on up to 16mp. However they are not able to capture images at 30 fps. They typically are only capturing 3 to 7 fps. Megapixel cameras can display higher than HDTV resolutions on PC monitors that support higher resolutions.

Take a look at the chart below to see how some of the more common resolutions compare.

How does CCTV Resolution compare to other standards?

Designation	H x V
CIF	352 x 240
2CIF	704 x 240
4CIF	704 x 480
D1	720 x 480
720p HDTV	1280 x 720
1.3MP	1280 x 1024
2MP	1600 x 1200
1080p HDTV	1920 x 1080
3MP	2048 x 1536
5MP	2592 x 1944
11MP	4000 x 2656
16MP	4872 x 3248

I hope you enjoyed this article on CCTV Resolution. If you have further questions please visit the Contact Us page on www.truvision.co.uk 

The Cost to the Public of Public Area CCTV?

The Cost to the Public of Public Area CCTV?

What actually is the cost of Public Area CCTV operated by your Local Authority per person per year in your community?

Go on, make a guess! Write it down and then compare it with the true figure.

I'm afraid I can't give you the exact figure for your Local Authority, but after a survey of many systems in the UK, I can give you the 'average costs' of such systems. Are you ready to be surprised? Then the answer is £2.03 per person in the authority area PER YEAR! Say the about equivalent of £10 per familyper year

Surprised, then so was I, and the cost ranges from 30p per year  per person to a maximum of £4.07 per year per person.

Isn't that incredible value for money? Well we have more statistics that show what is achieved for that incredibly low cost, and conversley what is risked if your authority decides to close the system, or reduce operating hours etc to save money for budget cuts.

These costs originate from a survey the CCTV User Group carried out of its members systems (still ongoing so any changes will be updated here as more statistics come available this is the position on 12/09/2011, with about 10% of all Local Authority Public Area CCTV systems responding, covering approximately 10% of the UK population. The number of cameras however implies it could at this stage be skewed towards the larger systems).

They above figures are based on the annual operating cost per year of the system, divided by the resident population of the authority area.

So what do these systems achieve?

I am sure you have seen the benefits and achievements of Public Area CCTV during the recent riots, but for more information on the value of CCTV in identifying culprits in them can be seen on the August 2011 fly-out menu for Exploding the Myths'

  

Statistics of CCTV System Achievements

	Number of Incidents recorded by CCTV Systems	Percentage originated by the Operator	Number of Video Reviews	Number of Evidence Discs Seized	Number of Arrests witnessed by CCTV System
Highest	16,973	90%	3,500	1,494	2,302
Average	4,885	42%	1,140	699	807
Lowest	215	9%	125	100	15

Now many of you might be wondering about the significant range of costs and values in these results. The problem is no two systems are alike. Some might be very small and some quite large. Some are inner cities and some more rural shire districts. Different systems also have different approaches to recording such statistics, and in others many control rooms provide many other services apart from CCTV, eg Carelines for vulnerable adults, or out of hours emergency telephone response for the authority. As it is often difficult to accurate sub-divide these costs with the same staff dealing with all these functions it is difficult to be precise. But they are offered as an indication.

So, that's the cost per person and what that money achieves, but on a daily basis what does it cost to run the CCTV system and what does that achieve?

  

The Cost of Operation of a Public Area CCTV System  £

	Cost per Authority Population	Cost per Incident Recorded	Cost per arrest witnessed	Cost per hour of Operation
Highest	4.07	953	1,000	91.32
Average	2.03	163	475	36.62
Lowest	0.30	16	65	4.26

Of these I think the most telling is the average cost per hour of operating a Public Area CCTV System. At less than £40 per hour for a 24/7/365 service it probably doesn't match the cost of the equivalent 1 Police Officer 24/7/365. But in CCTV terms the average system provides the equivalent of about 150 pairs of eyes, and the ability to record the evidence in a manner that the event can be graphically illustrated by recorded images.

Dome Cameras Vs PTZ Cameras

What are the differences between these two security cameras? They both look like domes right? Both security cameras are both great in design, and appeal. However, they have  major differences. Those differences start at the insides of the cameras. 
PTZ security cameras have a super brain inside their smoked color domes. The brain of a ptz camera, has artificial intelligence. Most ptz security cameras have to be manually zoomed in and out. They also pan both left and right. Seems that compared to regular dome security cameras they are just far more advanced. 

Dome cameras have the ability to have a fixed lens, or a varifocal lens built into the base of the dome.  Dome cameras can never be manually controlled. They can never be zoomed in and out or panned side to side.  There are many different sizes and styles of ptz cameras. Ptz security cameras can be made into "recess mounted" domes. They are so small that they look like dome cameras. With their smokey domes, it would be hard to know if the dome was looking at you, or that it is zooming in and out. Recess mounted ptz cameras could fit into residential communities and never be reported because they are so small. 

Just know that when trying to compare these two cameras it is not even a contest. Dome cameras are just not in the same class as ptz cameras. When you look at the price tag between the two, you can understand why they are in separate classes. When it comes to surveillance systems it really does not matter which camera is more powerful than others. It is about what it can do in an overall security setup. For example, if you have an indoor CCTV setup, then having ptz security cameras will not do you much good, in that they are too powerful. Instead a collection of fixed dome cameras with 3.5mm lens will do better. 

PTZ cameras are meant for an entirely different purpose. So you can see why we can say, the fight between which camera is the best becomes a no contest. In the end neither camera can out do each other. Choosing the right camera depends on what you need to accomplish in your security needs. But for the record PTZ cameras have the best technology, and are far more superior than dome cameras. However, dome cameras are more versatile and are cheaper than ptz cameras. So we declare this bout a "no contest"!

Why CCTV is important for your business?

CCTV integration is important for all businesses small or large.  Whether you own a small bakery or a retail store, having that assured security is important for the overall success of your business.  Many business leaders and owners can be hesitant on installing such features.  Cost and labour often sway business owners from the idea, however it should be known that it is an investment for the long run.  Why should businesses invest in CCTV systems? Check out these things you need to know about integrating it into your business.

1. CCTV cameras are great for scaring off would be burglars.  Even the sight of cameras in the region make crooks think twice about breaking in, let alone entering the property.
2. CCTV surveillance systems are cost effective.  They are easy to maintain and relatively inexpensive.
3. CCTV cameras can’t be avoided.  With systems utilizing multiple cameras, you can rest assure that all angles of the area are kept taps on.
4. Why wouldn't you want to keep your business safe? All businesses are vulnerable to theft.  Whether it is a cash register or valuable merchandise, utilizing CCTV systems is excellent for providing 24/7 coverage.

Features of Integrating CCTV Surveillance Devices:

CCTV Camera Interface:

Network cameras on common platform

Integrated CCTV photo-frames

Door Alarm connected to cameras

Software selects camera for Guard-watch

CCTV Multiplexer Integration:

Multiple cameras on common network

Multiplexers integrated with software

Recording on network server

User-friendly review and analysis

Video / Photo-Frame Data Recordings:

System stores photo-files on database

Subsystems integrate photo-frames

Stores data + photo-frame on same file

Easy to review and print all data

Dome Cameras vs Bullet Cameras

 

So what is the big deal about dome and bullet cameras? What are the key differences? How do they compare against each other? Both Dome Cameras and Bullet Cameras basically have the same working parts: a lens, circuit board, chip-set, and casing. So where do they differ?

"Should I buy a dome camera or a bullet camera?" many people ask. We hope this flowchart will make your decision making process easier.

Bullet Camera vs. Dome Camera Flowchart

For an explanation of the bullet vs. dome camera flowchart and links to further information see the information below.

Differences between Dome Cameras and Bullet Cameras: Shape

Let's start out with what is most obvious: shape and how that affects the way that you mount the surveillance camera.

Dome Cameras are circular dome (!) shaped cameras that hang from the ceiling.

Bullet cameras usually mount to the side of a wall and look like the barrel of a shotgun or a bullet casing.

When it comes to deciding which camera to use, it almost always comes down to this:

Do you want to hang it down from the ceiling, then use a dome camera.

Or on the side of a wall, use a bullet camera.

Comparison of Bullet Cameras' and Dome Cameras' Features

However, there are some technologies that are (for the most part) unique to either dome or bullet cameras. These technologies can sway one to purchase a bullet or a dome camera even when the default mount isn't ideal. (There are mounting brackets that can allow bullet cameras to be mounted from above, and brackets for dome cameras to mount from the side of a building).

1. If you need one of these features unique to Dome Cameras, this can sway you to purchase that type of camera over the a Bullet.

Vandal Proof Domes - This is a protective casing around the dome camera that keeps it from being damaged. They can withstand damage from projectiles and bats.

"Smoke" Domes - A smoke dome has a casing that makes it difficult to see where the camera lens is facing.

2. If you need one of these features unique to Bullet Cameras, this can sway you to purchase that type of camera over the a Dome.

Long Range Cameras - A Dome camera's dome restricts the size of the camera lens. If you are looking for a Long Range Camera, a Bullet Camera or C-Mount Camera is the way to go.

Outdoor or Weatherproof CCTV Cameras - If you are looking to install the camera outdoors, you should be considering bullet cameras for the reason of mounting already, but you should also do so because bullet cameras are much more likely to be weatherproofed. Reminder: Dew (not just rain or snow) can wreck a surveillance camera; just because a security camera is shielded by a overhang does not mean it won't be damaged by the moisture in the air -- especially in more humid climates.

Article by www.truvision.co.uk

Camera Styles Tutorial 2

Cameras come in different shapes and sizes, however this does not affect the picture quality. The shape rather should be looked at in terms of cosmetics, convenience of installation and camera placement. Two cameras with different housings and similar components should perform no different if constructed properly.

Box Cameras

Box cameras are often used when:

• Mounting to a wall or any vertical area
• Viewing long distances where a long lens is required which would not fit inside a dome or bullet camera
• When extreme low light conditions are not a consideration

If the box camera is within someone's reach the camera is usually inserted in a protective enclosure. If the lighting is extremely low, box cameras can be inserted inside enclosures that have built-in infra-red illuminators but the camera must be infra-red sensitive. Meaning it is able to utilize the infra-red illuminators from an external source.

Infra-red Cameras

Infra-red cameras are often used when:

• There are poor or extreme low light conditions
• When the camera is not within someone's reach

The distances infra-red cameras can see are based upon its illumination capacity. Infra-red cameras have LED's which cast out into the darkeness. Realistically agood rule of thumb is figure 1 foot for each LED. Therefore if a camera has 30 LED's then most likely the distance the camera covers is 30 feet.

Stay posted for the next review....