HD VS SD

CCTV is a fast moving market at the moment with many new technologies being introduced to enable higher quality images at lower cost but this can lead to confusion as to which is best. Here at HDCCTV we offer the following technologies

  • 2 and 4 MEGAPIXEL Cameras and Recorders are available
  • This system uses low cost computer network cables and your broadband router, no other cables are required, making installation quick and easy.
  • IP CCTV Cameras can be located anywhere in the world and their images be recorded and monitored live from one central point, or many places around the globe making it the most flexible cctv system available
  • 1080P or 720P HD images, AHD Version 1 is 720P HD, AHD Version 2 is 1080P HD
  • Uses standard coaxial cables or CAT5 computer networking cables, perfect for upgrading to HD without upgrading your cables.
  • The recorders are backward compatible with standard CCTV so no need to throw way old cameras when upgrading the system

 HDCCTV  – FREQUENTLY ASKED QUESTIONS

DO I REALLY NEED A HD CCTV SECURITY CAMERA SYSTEM ?

WHICH HDCCTV SYSTEM IS BEST –  AHD or HD IP?

WHICH CAMERA IS BEST – BULLET OR DOME CAMERA?

WHAT IS THE DIFFERENCE BETWEEN A FIXED LENS AND A VARIFOCAL LENS CAMERA? 

 WHY WOULD YOU WANT TO CHANGE THE VIEWING ANGLE OF A CAMERA?

CAN I ZOOM IN WITH HD CAMERAS EITHER LIVE AND WHEN PLAYING BACK?

WHAT IS THE NIGHT VISION LIKE?

HOW DO I CAPTURE NUMBER PLATES?

WHAT ABOUT FACIAL RECOGNITION?

HOW LONG WILL THE DVR STORE THE RECORDINGS FOR?

CAN I REMOTELY ACCESS THE CCTV SYSTEM?

  •  

FAQ  ANSWERS

DO I REALLY NEED A HD CCTV SECURITY CAMERA SYSTEM? 

That depends if you want to OBSERVE or IDENTIFY

OBSERVE – Any working camera system will let you observe people, objects, vehicles etc, but you wont necessarily get a clear image, perhaps if the person or object is close to the camera then it wouldn’t be a problem to identify them, but if they’re more than a few feet from the camera it can be a problem due to low quality pictures, and this can be a huge issue if you need to positively identify someone, after a burglary for example.

IDENTIFY – How many times have you seen a fuzzy blurry photo on Crimewatch or in your local paper? poor quality cameras are almost as useless as having no camera at all.   the ONE THING that should be uppermost in your mind why are you buying a video system is IMAGE QUALITY. the one thing that will prove a crime easily, the one thing that removes any doubt of what happened, a fuzzy picture will give you a clue what happened but the proof is in the detail

Here are examples of standard resolution and high definition cameras, this is how they look when showing full screen on a modern TV

 CLICK ON THE IMAGES BELOW TO SEE THEM FULL SIZE.

CLICK AGAIN TO SEE THE IMAGES ZOOMED IN – PAY PARTICULAR ATTENTION TO THE DETAILS, NUMBER PLATES AND GENERAL IMAGE SHARPNESS WHEN FULLY ZOOMED IN

STANDARD DEFINITION EQUIPMENT

 STANDARD DEFINITION EQUIPMENT

WORST STANDARD DEFINITION 

The image above is 320 x 240 pixels in size, commonly known as CIF.CIF resolution is rarely seen in any but the cheapest cheapo cctv equipment you’ll find on that auction site.

AVERAGE STANDARD DEFINITION 

This is in standard resolution known as D1. D1 is 720 x 576 pixels, it looks a lot better than CIF. Commonly sold in nationwide electronics stores and many online stores.

BEST STANDARD DEFINITION

960H is the highest standard definition CCTV system, still sold by many companies, 960H is 960 x 576 pixels, it is basically widescreen format D1

WORST HIGH DEFINITION – 720P

Here is a 720P high definition image, 720P is 1280 x 720 pixels.

BEST HIGH DEFINITION – 1080P

The image above is a full HD one, 1920 x 1080 Pixels. This is the same resolution as broadcast by the BBC HD channels

ULTRA HIGH DEFINITION – 4 MEGAPIXEL

Finally here is the highest resolution currently available, 4 Megapixel. The pixel size is 2592 x 1520

As you can see there is not a massive difference between the higher standard definition and lower high definition resolutions when looking at the wide angle view or looking at the image on a small screen, its only when you zoom into the images to look at details does it become obvious why HD is preferable.

Here is a small section of the picture above shown zoomed in – CLICK TO ENLARGE

320 x 240 Pixels Standard Definition – CIF
720 x 576 Pixels Standard Definition – D1
960 x 576 Pixels Standard Definition – 960H
1280 x 720 Pixels High Definition – 720P
1920 x 1080 Pixels High Definition – 1080P
 2592 x 1520 Pixels Ultra High Definition – 4 Megapixel

There is not a huge difference between 1080P and 4 Megapixel, even when zoomed in, 1080P AHD and HD IP equipment is more than good enough for most customers, but if you need that extra bit of detail then have a look at our 4 Megapixel cameras and IP NVRs

 

WHICH HD CCTV SYSTEM IS BEST, AHD or IP? –  Neither are better than the other, they both have their merits and strengths (shown highlighted )

 *  AHD Recorders are also compatible with older standard definition and 960H CCTV cameras

** The HD- IP Recorders are compatible with ONVIF compatible cameras. More information on ONVIF can be found HERE

  •  

 

WHICH CAMERA IS BEST – BULLET OR DOME CAMERANeither is better  – they are often the same camera in a different housing, the camera style choice is purely for aesthetic reasons. Some people prefer a camera to be discreet and dome style, others like a bullet style camera.

  •  

WHAT IS THE DIFFERENCE BETWEEN A FIXED LENS AND A VARIFOCAL LENS CAMERA?

A fixed lens is pre-focussed and its viewing angle is fixed, usually 78 or 92 degrees, a varifocal lens allows the installer to set the viewing angle manually using just a screwdriver, the viewing angle can be set between 23 and 92 degrees.

An example of when a fixed lens camera would be used  would be a small camera mounted above a front door to see any callers, a fixed lens wide angle camera will clearly see anyone near or at the door, as well as giving an overview of the front area of the property

 

  •  

 WHY WOULD YOU WANT TO CHANGE THE VIEWING ANGLE OF A CAMERA? To make distant objects appear closer, to zoom in

Using the image above, see that little black car in the top left corner, whats the registration number?  Try clicking and zooming into the image, the number plate is too small to read even when zoomed in.

A varifocal lens lets you set the camera viewing angle from wide (92 degrees) to a narrow view (23 degrees) and anwhere inbetween.

Doing this brings distant objects closer and therefore makes them clearer.

 

Heres that little black car again, the camera lens is zoomed in. you can now read the number plate, but at the cost of the wide angle view

This is why a varifocal lens is best so you can set the best viewing angle for each location, not too wide and not too narrow

To explain the point further – Football on TV…. love it or loathe it everyone has seen football on TV at some point

In this first image we can see a lot of the pitch and the players on the pitch in this wide angle camera shot, but the players are tiny and its impossible to make out a face of a player

 

But now looking at this shot of this poor fella hobbling off to oblivion, you can see the camera viewing angle is much narrower, the lens is zoomed in to a significantly smaller area of the football pitch and now its easier to make out the faces & details simply because they people in the shot are much larger.

This applies to all video cameras no matter their cost, including CCTV cameras – the more area the camera can see, the wider the viewing angle the smaller everything will be on screen, the smaller things are on screen the less detail you will see.   A varifocal lens lets you or the installer set the perfect viewing angle for every camera position, increasing the chances of identification.

  •  

CAN I ZOOM IN WITH HD CAMERAS LIVE AND WHEN PLAYING BACK RECORDINGS? Digitally yes, the DVRs and NVR recorders have digital zoom functions, just like when you zoom in with your smartphone camera, it will not make the object any clearer, only larger

If a clear, remotely controlled zoom is required the only choice is to have a camera with motorised zoom lens, such as our PTZ (Pan, Tilt, Zoom) cameras, these will do the job very nicely but they are an expensive option.

AHD PTZ Cameras

HD IP PTZ Cameras

WHAT IS THE NIGHT VISION LIKE?  We think its pretty impressive. Have a look at a few night snapshots below all taken using our cameras,

Click to enlarge the images

 

Our higher end Xvison Cameras have a function called Smart IR, it automatically adjusts the IR level as required which is especially important as the camera is approached, it avoids the “ghost” look.

The images below illustrate what Smart IR does.

Smart IR OFF

Smart IR ON

Smart IR OFF

Smart IR ON

 

  •  

WILL HD CCTV EQUIPMENT CAPTURE NUMBER PLATES? During the daytime it is not a major problem to read number plates, all you need to do is set up a camera to capture the plate, make the number plate as large as possible on screen and it will capture it, if the camera viewing angle is too wide the number plate will be too small and will not be readable.

Night time number plates is a different story…what happens is the Infra Red light that the camera gives out bounces back off the plastic plate and shows on screen as a white glowing rectangle. This is why on motorways where there are cameras there are lights

There are specialised number plate cameras available but these are costly and more importantly they are only useful for capturing number plates, they acheive the number plate capture by dimming down the whole picture by closing the iris so much that the plate becomes readable, but this darkened picture makes them useless as a general purpose security camera.

 The best solution for capturing number plates at night is a three point method….light it up, slow it down and zoom it in. Light up the car with a security light, this switches the camera to daytime mode, slow the car down with traffic calming methods to reduce image blur as much as possible and zoom it in, make sure the number plate fills a significant portion of the overall screen, doing all three of these will capture number plates, doing any less than the three things will reduce the chances of capturing plate 100% of the time.

  •  

WHAT ABOUT FACIAL RECOGNITION? Any HD 1080P or 4 megapixel system will be clear enough for facial recognition provided the subject is large enough on the screen

Please watch the video below, during the video you will see people several times, see how far away they are before you cant make them out clearly.

 

  •  

 HOW LONG WILL THE DVR STORE THE RECORDINGS FOR? This depends on how many cameras you use and how big the hard drive is. As a rough guide one camera recording constantly for 24 hours a day will use 95GB of hard drive space.

The DVR can be programmed to record constantly or only when motion is detected, this saves lots of hard drive space because you are not recordings hours of nothing

CAN I REMOTELY ACCESS THE CCTV SYSTEM? Yes from anywhere in the world via any internet connected device, all of our systems come with free PC and Apple Software and free mobile apps are available for iPhone/iPad and Android smartphones and tablets.

Click on the images below to view our videos showing the remote software in use.

The first video shows you how the software works when using the system remotely on Windows and Apple Mac computers.

The second video demonstrates the mobile software for iPhone iPad and Android smartphones and tablet computer