Showing posts with label dome cameras indoor cameras surveillance cameras cctv kits cctv systems DVRs. Show all posts
Showing posts with label dome cameras indoor cameras surveillance cameras cctv kits cctv systems DVRs. Show all posts

Monday, 12 August 2013

STARLIGHT CAMERAS

Starlight Cameras, and Color Slow Speed Shutter Camera

We offer starlight cameras, color slow speed shutter cameras, lowlight cameras, and other specialized equipment.

The Starlight camera is 30x more sensitive to light than standard low-light cameras. Lux .0003. Res:570 lines

Infrared light source works with infrared cameras to see in total darkness.

Below are a series of images that compare starlight cameras, color slow speed shutter cameras with lowlight cameras, and also the failure of standard video surveillance cameras to see an image adequately in dark and no-light locations. All video captures were taken at night.
Here are some images that show the abilities of the starlight cameras, color slow speed shutter cameras, vs lowlight cameras, and also the inability of normal video surveillance cameras in the dark and lowlight applications.

www.truvision.co.uk 

Lowlight Cameras VS. Starlight Cameras
normal CCTV CameraStar light camera
Here you can see the difference between a normal surveillance camera and astarlight camera at night.
quad DVR with starlight camstarlight no artificial lighting
The picture on the left is showing a four camera system with one of the cameras as a starlight camera. The picture on the right is from a starlight camera with no artificial lighting in immediate area.
starlight video camera storage unitsstorage unit protection
These two pictures show what the the starlight cameras are capable of. Notice that the lights are out in both pictures.
video without moonlightvideo with moonlight
The picture on the left is taken without moonlight.
On the right the picture taken with the illumination of the moon.
Color Slow Speed Shutter Cameras - Excellent for terrestrial viewing.

Wednesday, 31 July 2013

CIF vs D1

CIF vs D1


d1 vs cif resolutionCIF and D1 represent different resolution standards in DVRs (Digital Video Recorders - they record analog cameras).

CIF DVRs have a 360 x 240 pixel resolution.
D1 DVRs have a 720 x 480 pixel resolution.
This means that D1 is roughly four the image quality level of CIF.Image quality can be very important and can be the difference between getting a blurry representation of someone and knowing exactly who it was. 

Our Econ line of DVRs record in CIF, while our Standard line records in D1.

CIF and D1 sample VIdeos

Make sure you click the white "four arrows" button near the SCW logo to see these videos in their proper resolution.
CIF Resolution
D1 Resolution

In case you didn't want to watch those video, here's an image from them.
CIFD1


Why CIF and D1 aren't the only things that matter

Better Image Quality Does Not Always Mean Better Video Quality

Framerate
Video Quality is dependent upon two things: image resolution and frames per second. Resolution improves image quality (which is why the videos above show a color swatch that doesn't move) while frame-rate improves video quality by preventing motion blur.
When purchasing a DVR it is always very important to also check the frame rate.Make sure it can record at 30 Frames Per Second (which is known as "realtime recording.")

Part of our 100% Satisfaction Guarantee is that All of our DVRs record at 30 FPS.


Buyer Beware: Some companies sell inferior "D1 DVRs"

Each DVR has a recording resolution and a live video resolution. D1 is currently the highest analog resolution used for both recording and live viewing, but many standalone DVRs are not able to record in D1 in realtime, which is 30 frames per second (fps). Because significant processing power is needed to record these high resolution images and it that much power wasn't available or economical then, D1 originally was not able to offer the same number of frames per second as CIF.

Nowadays with computing power being what it is, D1 DVRs can record at full 30 fps frame rates. However, some competitors obscure their frame rate by saying things like "FPS is 60" which makes their frame rate sound higher, however they often mean by that is "The Total FPS of all the cameras combined is 60." For example, if Total FPS is 60 than the frame rate is 15 per camera if there are 4 channels, or 7.5 FPS if there are 8 cameras.
Most people are unable to tell the difference between 30 FPS and above, so you don't have to go too much higher than 30 FPS, however, below 30 FPS can cause the video to be so "jerky" as to be unwatchable.

CIF and D1 aren't the only options

Nowadays, there are actually 4 resolution options for CCTV recording, but most DVRs can only handle CIF or D1. If you want HD recording, you will need to switch from analog cameras and a DVR to IP cameras (cameras with Internal Processors and which connect to a network and have IP addresses) and an NVR (Network Video Recorders - they record IP cameras).
IP cameras can record in 720p or 1080p (and also D1 and CIF).
Click here for a page similar to this one that compares 720p and 1080p resolution
The image below shows the relative size difference in image size (while keeping the pixel size constant) for CIF, D1, 720p, and 1080p. Each size increase is about 4 times as many pixels as the one before it. 

Note: your resolution won't prevent you from capturing a wide angle view, so you will be able to get a wide or narrow shot with any recording resolution. So, for example, you could record the whole scene below in CIF resolution, however, since it would only have as many pixels as are represented in the CIF area (360 x 240), it would be blurry.
all resolutions - cif d1 hd720 hd1080p 


How to decide if you need a CIF or D1 DVR


When purchasing a DVR, you should ask yourself if you need the higher resolution. If you do, you should ask if you need the frame rate to also stay at Full 30 FPS recording. Here's a flowchart of the CIF vs D1 decision making process, and here are some links to

CIF DVRs

D1 DVRs

Full D1 DVRs

CIF vs D1 DVR Flowchart

www.truvision.co.uk

Wednesday, 24 July 2013

What is the best cabling for CCTV?

Tips for Installing CCTV Cameras with Long CCTV Cable Run

When you are installing a CCTV system in an office, house or small warehouse, it is usually quite easy to run the cabling. The cable will not often have to go very far, so you can use a standard CCTV cable and the video signal will be clear and sharp.

cctv long distance cable Tips for Installing CCTV Cameras with Long CCTV Cable Run
Tips for Installing CCTV Cameras with Long CCTV Cable Run










However, there are some situations where it might be more difficult to install CCTV. In a large building, factory, village, house compound or other large area, installing the cameras and the cabling will bring another set of challenges. You will need a lot more cabling and a much more well thought out approach in order to set up the cameras correctly.
What is the right approach for installing a CCTV system which will require a long cable run? There are a few things that you should keep in mind as you proceed.
Plan Ahead
Because you will be installing such a large system with a lot of cable length, you will need to make a plan for where your cables will go. First of all, get your hands on an area map or a floor plan of the building so that you can get a view of what you have to work with. You can look for the electrical room as well as already existing electrical pipes which are being used for other purposes such as radio equipment.
With this information, you can compute the distance and determine the best path for the cable to run along. Make a plan for how you will install the cable so that you know exactly what you are doing.
Choosing the Right Cable
When you are selecting the type of cable to use for the project, you should be using the highest quality cable available so that it will be strong enough to last for a long time. Make sure that the cable you choose matches the environment, such as whether the installation is indoors or outdoors.
It you find that the cable must be continuously flexed during use, such as when it is being used to connect pan & tilt cameras or scanners, then you should select a cable with a stranded wire core which will be able to withstand this movement. Cable which contains pure copper stranding is the best choice, as cable with stranding made from copper-plated steel will not effectively transmit in the CCTV frequency range.
If your CCTV installation requires a cable run of more than 800 ft, it is best to use RG6/U as this as a large-diameter center conductor and can deliver a signal further than other types of cable. If the installation requires a cable run of more than 1,500 feet, you might want to use RG11/U which is even larger and can transmit even further. However, keep in mind that it is heavy and difficult to install so will require a lot more work.
One of the best cables to use for long cable run are CAT5 cables, because they are more cost effective over long distances than coax cables and therefore will save you money. CAT5 cables are also much better at transmitting energy as well as video, so that the security cameras can be powered from long distances.
Another advantage is that the CAT5 cables have eight separate wires inside of them, so they are capable of supporting four channels at a time. You will also need Video Baluns, which are necessary for running your CAT5 cables over longer distances.
These are just a few important tips to keep in mind when you are installing CCTV cameras which have a Long Cable Run.

www.truvision.co.uk

Thursday, 18 July 2013

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.
Dvr1.png
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

Wednesday, 10 July 2013

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.
CIF352 x 240
2CIF704 x 240
4CIF704 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?
DesignationH x V
CIF352 x 240
2CIF704 x 240
4CIF704 x 480
D1720 x 480
720p HDTV1280 x 720
1.3MP1280 x 1024
2MP1600 x 1200
1080p HDTV1920 x 1080
3MP2048 x 1536
5MP2592 x 1944
11MP4000 x 2656
16MP4872 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