Posts Tagged ‘ resolution ’



Frame Rate vs Resolution in Security Cameras – What’s More Important?

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Monday, July 27th, 2015

Frame-Rate-Vs-Resolution

Frame Rate vs Resolution? Which is more important when it comes to the best recording with security cameras? This is one of the questions that I am asked the most at Techpro Security Products. It is an important question to ask at the time the purchase is made, but it’s also important to understand the answer when you are setting up the DVR or NVR to record in the manner that you want. This is true at both of these points in time for the same reason. It’s going to affect the quality of the recorded video and how much hard drive space you need to have installed in the recording device. There are actually two other factors that will affect the video quality which we’ll take a look at in this article as well: compression and the bit rate.

In the security camera world, the video quality produced and recorded by your system is very important. It can make the difference in your recorded footage being able to help law enforcement to catch those responsible for criminal activity or not. If your surveillance video doesn’t provide enough detail to recognize a person or vehicle, then it’s not going to be nearly as useful to investigators.

Resolution –

The resolution ratings for a camera or recording device are a measurement of the vertical and horizontal pixels which the device is able to process. The more pixels in an image, the higher the level of detail that will be displayed and/or recorded. The native size of each frame also increases in size as the resolution goes up and it will be possible to zoom in on the image to a greater degree without pixilation or loss of detail occurring. This means that not only will a camera offering megapixel video give you a much higher level of detail, but you will also be able to zoom in further.

The security cameras that we carry today are rated for resolutions ranging between 520 TVL (with an analog system) up to 2 Megapixels (with an HD-CVI system) or up to 8MP (with an IP camera system). No matter which type of system you choose for your application, you will be able to operate them at a lower resolution through the settings available in the recording device or the camera itself. The resolution that your security camera system is capable of processing is the basis for the video quality you will get but the following elements heavily influence the final picture quality:

Frame Rate –

All video is really a series of pictures or frames, just like the old flip books. As a general rule, the video’s animation will be smoother when you’re viewing more frames per second. This concept is the same as if you were to flip through a flip book at greater speed. Our DVR’s and NVRs give you the ability to customize how many frames per second are being written to the hard drive with the majority of resolutions which are available in the security camera industry today. The maximum frames per second is limited with higher resolution cameras (3 megapixels cameras and those with higher resolutions), but cameras of this type more than make of for it with incredibly high picture quality. This limitation exists because of the increased data required for these higher resolution cameras.

Compression –

Transmitting surveillance camera video requires a significant amount of data to be handled. The higher the quality of the video being transmitted means that much more data has to be processed. Without compressing this video, it really would not be possible for a security camera system to offer megapixel quality video. H.264 is the best type of video compression that is available today, although there are other types which are being researched currently and may be available down the road.

Generally, this type of compression sends a complete picture as one of the frames (referred to as an iframe), then in the next few frames it will only send the data for the portion of the frame that has changed. This allows the system to not have to resend the redundant portions of the picture again. This drastically reduces the amount of data that needs to be handled by the system’s processor.

The issue with this in relation to the video quality produced is that if you choose different types of video compression, or adjust how often the iframes occur, it can severely affect the picture quality that you get. Our DVRs and some cameras give you these configuration options in order to provide the high level of customization that will allow you to set up your security camera system to meet your needs in the best possible manner. It is a very good idea to contact our technical service department before making any changes to this portion of the settings menu.

Bit Rate –

This setting allows you set a limit on the amount of data transmission that each camera can use every second. The more data that is used by each camera means that it will be able to give you higher video quality, but it will take up more hard drive space. Since all of the DVRs and NVRs that Techpro Security Products carries are designed to overwrite the oldest footage once the storage space fills up, this is important. If you have the bit rates for your cameras set high enough so that they give the best video possible, it’s going to use up your hard drive space faster and cause it to be over written sooner.

It’s certainly understandable to want the best video quality possible but you need to understand everything that goes into that quality and make sure that your system is designed to meet your other needs. For example, this may be accomplished by installing additional hard drive space in order to get your surveillance system to hold the number of days of recorded footage that you want. Our sales team can make sure that the system is designed to meet your desires and needs. Our tech support team can also help you to make sure that everything is configured correctly on site, which is part of Tech Pro’s free service.

For a more detailed and visual look on resolutions, check out our resolution comparison page which included some side by side video comparisons.

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A Beginner’s Visual Guide to Security Camera Features

Written By:
Monday, December 29th, 2014

The security camera market today is a quickly evolving field with a multitude of camera styles and features to choose from. For beginners, this can be initially confusing especially when looking to purchase a multi-camera system. What features are most important, or more to the point, what features will be most important for your security needs? This article will attempt to help illustrate some of these security camera features with the help of some demonstration videos and graphics to help give you a better idea what features to consider when purchasing a security camera system.

1) Video Resolution

resolution

One of the first and most important things to consider when selecting a security camera is the video resolution. Older cameras used standard definition analog resolution and many cameras still made today also use this format. Due to the older technology, analog cameras do tend to be less expensive and offer the ability to record for much longer time periods while using far less memory / hard drive space. But, analog cameras do lack the fine detail that high definition cameras have. Megapixel, or High-Definition recording, generates an image that is several times larger than analog, which allows them the capability to capture far greater detail, including faces, tattoos, and other minute details that could be important if the footage has to be later used as evidence.

The higher the megapixel value of the camera, the more detail you’ll be able to discern from the footage. Keep in mind, as the resolution size increases beyond 1080p, the maximum frame rate will decrease. This is because each frame rendered at an extremely high resolution uses exponentially more memory and network bandwidth to encode.

This video will give you an idea of how the different resolution sizes and frame rates compare to each other.

For instance, a 2 megapixel (1920 X 1080 pixels) high definition security camera can easily record at a full 30 frames per second, but a 5 megapixel (2560 X 1920 pixels) camera will max out at 12 frames per second. Note: Higher megapixel cameras can also be set to lower resolution settings, with higher frame rates, if necessary.

3 MP vs Analog
Side by Side – 3MP vs Analog cameras @ approx. 20 feet away, digitally zoomed on both to show detail

Camera resolution will also factor into how much hard drive space you’ll need to archive your footage. The higher the resolution, and the more cameras you install, the more hard drive space you’ll need inside your DVR. Fortunately, most DVRs have the capability to hold several hard drives for storage. An easy way to figure out exactly how much hard drive space you’ll need for any given number of cameras is by using our Online Hard Drive Calculator

CCTV hard drive calculator
Screenshot of the CCTV Hard Drive Calculator

2) Infrared Mode

Some security cameras have a built in ability to see in complete darkness using infrared light. The way this works is infrared lights that surround the camera lens send a strong beam of infrared light (which is invisible to the naked eye).

These infrared LEDs switch on automatically when the lights are turned off or when the sun goes down and not enough visible light is hitting the camera’s image sensor. Some of that infrared light beaming out of the camera bounces back when it hits an object and that residual infrared light is captured by the Infrared sensor, which is usually directly above the lens of the camera. IR images usually lack color, but allow small, important details to be seen clearly.

OD-LX700IR50-B

The higher the IR rating of the camera, the further it can see into the darkness. For instance, a camera with an IR of 50 can see 50 feet, an IR of 250 feet can see 250 feet, and so on. NOTE- Be careful not to install a camera too close to another object, especially when installing a PTZ with infrared lights. This can cause the camera’s IR sensor to flood and will end up washing out any detail.

3) Lenses – Fixed, Zoom and Interchangeable Lenses

Many security cameras have static, fixed wide angle lenses, and are only intended to be used to capture an overall view of the environment. Varifocal lens cameras have the ability to go from a wide angle to a closer shot, and can be sometimes be controlled though the interface of a DVR or NVR, through a web browser, and others. However, most varificol cameras have a manual zoom and focus that need to be adjusted at the camera.

varifocal manual zoom lens
Some varifocal cameras need to be manually zoomed and focused. These controls are usually found near the lens. On dome cameras, it’s usually necessary to remove the protective dome to access these controls.

Interchangeable Lenses

cctv camera lenses
Fixed Lens vs Interchangeable lenses.

There’s a style of security camera that uses external interchangeable lenses rather than built in lenses. These are called “Box Cameras”. The lenses for these cameras can be purchased separately and are screwed into the front port on the camera.

The advantage of these cameras is that they can allow for exceptional zoom capabilities when paired with certain lenses, but they must be zoomed and focused manually via control knobs on the side of the lens.

This style of camera is also designed to be installed inside an outdoor camera housing, which protects it from the weather and supplies a cooling mechanism, and has a port for power.

camera housing article graphic
Box cameras can be easily added to a protective housing for outdoor use.

4) Pan-Tilt-Zoom

If you need to record an area where on-the-fly camera movement will be a necessity, and you don’t want the hassle of having to manually adjust, zoom and focus the camera, then a Pan tilt zoom camera is the best option. These cameras are typically rather large, so if you’re looking for a small, easily hidden camera, they may not be the best option. But, in terms of overall breadth features, Pan-Tilt-Zoom cameras (or PTZ’s) are truly state-of-the-art.

Here’s an example of a PTZ camera in action.

Due to their range of movement (which typically 360 degrees horizontally and 90 degrees vertically), PTZ cameras have an ability other security cameras are incapable of, such as the ability to detect and track movement.

Parameters can be created within the interface of your NVR such as a virtual trip wire drawn within the software in front of a doorway, as an example. When that invisible line is crossed, the camera will follow that movement until the person or object goes out of frame.

virtual tripwire
A user can create a virtual tripwire, so anything that crosses the line causes the camera to start tracking that moving object.

Additionally, parameters can be set to tell the camera what movement or areas within the camera’s view to ignore while it’s tracking movement, such as windblown trees, clouds, or small objects such as birds. All of these might trigger the camera to start tracking otherwise.

You can also set a PTZ to look around a given area on a predetermined scan cycle, and these cameras typically come with several of these cycles pre-programmed into the camera itself.

5) Wired versus Wireless

Many people have asked us why we cannot recommend a wireless security camera. The answer is simply that the battery technology needed to make wireless security cameras viable isn’t quite there yet. Cameras need a constant, reliable source of power, and there hasn’t yet been a battery designed that can run a security camera for days or weeks on end. So, for the foreseeable future, wired security cameras will be the standard.

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Security Camera Lines Of Resolution

Thursday, January 19th, 2012

Security Camera Lines of ResolutionOne of the most important specifications to consider when making your decision to purchase a security camera system is the camera resolution. If you don’t have the right camera resolution, you may end up allowing the person who committed the crime to be able to walk away due to the lack of picture quality. On the other hand, if you have exceptional quality in your new security system, you may end up being able to apprehend the criminal and get justice.

The size, fineness, or picture quality and video quality are all determined by the security cameras lines of resolution. Television lines are typically used to reference this figure and provide the type of analog video quality. In terms of digital resolution, they are usually referred to as pixels. If you take a look at both of the aspects, you will see how the lines of resolution are able to be related to picture quality in a security camera.

In order to begin, there are multiple video formats that are used based on the geographical area that you are located. National Television System Committee (NTSC) is used mainly in North America, South America, Taiwan, Japan and many other locations as well. Phase Alternating Line (PAL) can generally be found in Africa, Asia, Australia, New Zealand and almost all of Europe. In Africa and the Russian Federation you will find Sequential Couleur a Memoire (SECAM). The English version of SECAM is Sequential Color with Memory. The main focus of this article is going to revolve around the NTSC format.

There are 480 interlaced horizontal lines that make up the standard National Television System Committee analog video. You have to vertically count the amount of horizontal lines that are displayed, while one is above the other and so forth. The resolution of security cameras are in Television Lines, which specifies the amount of vertical lines that are able to be seen within a given area of a monochrome picture to determine the horizontal resolution. The amount of vertical lines is counted on a horizontal basis, with one being right next to the other. The amount of scan lines is not exactly equal to the Television Lines, but it is affected by the amount of scan lines that are available.

How are Security Camera Videos Displayed?

Security camera videos are generally displayed in a three by four ratio. You can think of this in terms of a rectangle, such as it is three units wide by four units in height. The resolution horizontally is equal to the amount of vertical lines that are measured. You are actually measuring the amount of detail that is visible when you are able to see ¾ of the width of the picture, or 75 percent. The amount of vertical lines that are being used by the Television Lines is three units. For example, if you have a television picture that is three inches wide by four inches high with a Television Lines rating of 480, you are actually going to have 480 vertical lines within that three inch width.

How does the Resolution of Different Security Cameras Vary?

There are a wide range of security cameras that have different specifications based on the various types of manufacturers. It is also based upon the price and the different uses of the security camera. As a general rule, the typical CCTV camera is going to have a resolution of approximately 380 Television Lines for a standard camera. On the other hand, if you have a high-resolution camera then you will find a CCTV with a resolution of around 540 Television Lines.

The actual quality of a security camera can be measured by the Television Lines resolution. This is completely different number than the actual horizontal number of scanning lines for broadcast TV systems.

Analog videos are given different lines of resolution that apply to them. When you look at the different digital video resolutions you will notice the difference. You will find that the digital video is still being displayed in the typical three by four ratios. The total resolution is still measure in pixels, which are small points, dots or squares. Digital cameras are going to have a sensor just like the regular analog cameras. This sensor is called a Charged Coupled Device (CCD), which allows you to capture the picture within a digital format. The resolution for a digital picture is commonly referred to In terms of pixels, such as 352 x 480. Some of the most common resolutions for your digital security camera include: 704 x 480, 352 x 480 and 352 x 240.

You have to remember to keep the resolution of the camera display separate from the amount of pixels within the CCD. There are literally millions of light sensing cells within the CCD sensor. The pixel count is determined by the amount of pixels that are produced by the sensor. As an example, if a camera is capable of producing an image that is 640 x 480, it would contain approximately 307,200 pixels. A lot of people assume that a CCD rating in megapixels is the camera resolution, but this is a false misconception. However, what it does indicate is the amount of potential resolution that the camera has available to produce when combined with other high-quality equipment. Some of the typical types of high-quality equipment are monitors, processors, and others.

When you put everything into perspective, you can see the comparison between analog Television Lines and the digital resolution. The picture quality is going to keep increasing along with the number of lines increasing.

Digital Signals

1. 352 x 240 pixels
2. 704 x 240 pixels
3. 704 x 480 pixels

Analog Signals

1. 330 TVL
2. 380 TVL
3. 480 TVL
4. 570 TVL

Determining the Picture Quality of a Security Camera

One of the most important notes to remember is how to determine the final picture quality. Security cameras, whether analog or digital, are going to have varying picture qualities that are going to play a part in the final picture quality of the digital camera. You can say that your final picture quality is only going to be as good as the absolute lowest component that is used in your whole system. For example, if you were to use a 570 Television Lines resolution on a 330 Television Lines monitor, you are only going to be able to view your camera images in 330 Television Lines resolution. Make sure that you are getting the most that you can out of your security system by choosing components that are compatible.

Your whole system is only as strong, or as weak, as we choose to make it. If you have equipment that is various resolutions, you have to remember that the main things you have to be concerned with are the higher and lower screen resolutions. If you have a monitor that has a resolution of 500 lines, a security camera that is 420 lines of resolution and a recorder that has a resolution of 250 lines, you are going to get a picture that will top out at the 250 lines. While you may be able to look into the monitor and see an exceptional picture, you are only going to get as good of a recording as your equipment allows. When you choose to determine what type of resolution you are going to get, make sure that you try to choose equipment that is going to complement each other. You have to take the time to consider everything that you are going to be using in order to make sure that you choose accordingly.

How Important is the Resolution of a Security Camera?

Resolution is extremely important when you are trying to determine what your recording is going to look like. You are not going to have to worry about what your picture quality is going to look like when you take the time to go through every piece of equipment that you are going to buy. If you make sure that everything is going to go along with each other, you will save yourself a lot of hassles and headaches in the long run. You won’t have to worry about the what-ifs if you take the time to debate everything before you make your purchase. It is better to take a little extra time beforehand and decide which resolution is going to be perfect for your wants and needs. This will help you to eliminate any frustration later on when you are trying to figure out what makes the difference in the resolution.

There is a lot more to screen resolution than just a number, and the more that you can understand everything the better it is going to be in the end. Even though it may be confusing for a lot of people, there are experts who can help to guide you in your purchase. They will help make sure that you are not going to have to deal with a bunch of equipment that is not going to work together in the manner that you had once intended. Go through everything as much as you can and decide just how much detail you are going to need for your home or business. Enjoy everything that your security camera lines of resolution can bring to the table for years to come.

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Security DVR Recording Resolutions

Friday, March 19th, 2010

You’re in the market for a security surveillance system for your home or your business. What is the one most important component of that system? The Digital Video Recorder, or DVR, is the single most important component. And the most important aspect of choosing a DVR is the recording resolution.

In manufacturing a DVR, the recording resolution is a balancing act between being able to actually see what’s being recorded and having the storage space to store the video. The better the resolution, the better the images look, but the more space it takes to store it, and the beefier the processor it takes to record it. Manufacturers try to offer that ideal balance between being able to actually have usable recorded footage for evidence of an event if needed, being able to process the enormous amounts of data involved while recording it at a usable resolution, and not running out of recording room to store events. How the manufacturers succeed at this is what you need to evaluate when shopping for DVRs. Budget will be a huge consideration here, since the units that juggle these factors in the most optimum way are, of course, the most expensive. Putting together the optimum system which takes into account all your needs, including your budget, and gives you recordings from all DVRs that can actually be used as evidence takes a bit of knowledge and the help of a qualified reputable professional.

When referring to recording resolution the industry usually uses either a variant of CIF, which is 360 x 240 pixel resolution, or D1, which is 720 x 480 pixel resolution. There is a distinction that needs to be addressed here. Each DVR has a recording resolution and a live video resolution. The live video is always going to be clearer, so when you are evaluating DVR units you really need to know how the recorded video will look, since that will be your actionable evidence in the event of a security problem. D1 is currently the highest resolution used for recording, but most standalone DVRs are not able to record in D1 in realtime, which is 30 frames per second (fps) on all the channels at the same time, though some of the new units coming out are starting to improve on that.

The strength and capacity of the processor that is running the DVR will determine how high a resolution can be set for recording. The memory in the unit is also a big factor. Most processors can’t yet record at a realtime resolution, though some of the newer units that are beginning to show up in the marketplace are hitting 4CIF recording in real time on all channels, which is a 704 x 480 pixel resolution. The current average for a DVR is a CIF recording resolution, which is 360 x 240 pixels in real time at 30 fps.

When looking at the specifications, the three things you need to consider together are the recording resolution, the frame rate, and the recording speed. Of the three, the recording resolution carries the most weight in a carefully considered purchasing decision. If there is a security event, you want to be able to clearly identify the face of the person involved, and if the resolution doesn’t allow this, it’s useless. A 640 x 480 recording resolution is the minimum recording resolution which will easily allow this. 720 x 480 has the same quality but in a wider screened aspect ratio to allow viewing on the typical widescreen computer or tv monitor. 1600 x 1200 is ideal for viewing from an actionable standpoint, but the speed, storage and processing needed to maintain this recording resolution make the cost prohibitive for all but the most deep pocket organizations.

When putting together a budget system, the best way to approach it is to choose a better resolution for key points of security, ie near the front door and the cash register, while choosing lesser resolutions for areas which would be more likely to be monitored in realtime but where recording resolution is a bit less critical, and would simply be support footage when combined with the higher resolution footage from the other areas, not an ideal approach, but one which would allow security on a smaller budget.

Whatever your security needs, the help of a qualified and reputable security monitoring specialist will shortcut your efforts enormously. Juggling all the factors involved in the purchase, including the recording resolution needed for actionable evidence, is key to the overall success of your security efforts.

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The Difference Between CIF And 4CIF Resolution

Thursday, August 13th, 2009

4CIF Resolution Image
When configuring your DVR for optimal recording, there are many options you will be considering. Among them is the resolution you want to record in. While most DVR’s can record in CIF resolution (360×240) at the maximum frame rate provided by the DVR, some can also record at higher resolutions by reducing the frame rate. For example, you may be able to record on any channel at CIF resolution at 30 frames per second, but then you would probably only be able to record at 7.5 fps per second if you changed the resolution to 4CIF (704×480). You will have to decide for each camera (assuming your DVR has independent resolution settings for each channel) which resolution you want to record in. Remember, what you see is not always what you get! Most DVR’s will display live video in 4CIF or D1 (720×480) resolution, but they are often recording in a much lower resolution.

Each application has different needs. If you are using the security camera for a general overview, you may want to use CIF resolution and the maximum frame rate since detail is less important and fluid video is probably more important. On the other hand, if you are using the camera for facial recognition at the front door of your business, then you will surely want to record at 4CIF resolution, even if it means sacrificing some of the frame rate. The 4CIF image is literally 4 times larger than the CIF image and therefore can provide you with 4 times the detail. There are a couple of DVRs out there that can give you the best of both worlds, 4CIF resolution while doing 30fps recording on every channel. At this time, I only know of one unit that can offer that. It is the Ultimate Series DVR.

Here are 2 different images taken from an Elite Series DVR. The smaller image was from a CIF (360×240) recording and the larger image is from a 4CIF (704×480) recording. The difference between the two is the size of the image stored on the hard drive.

CIF Resolution

CIF Resolution Image

4 CIF Resolution

4CIF Resolution Image

As you can see, the 4CIF image is much larger. It will be much easier to capture details from the 4 CIF resolution image, than from the CIF resolution image. Unless you are lucky enough to be working with a DVR that does 4CIF or D1 recording in real time (30fps) on all channels at the same time, you will need to decide for each camera, which resolution is best for that application.

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