The term Bullet Camera comes from its resemblance to a rifle bullet. Generally long and tapered like a cylinder, it looks like an oversized ammo cartridge. Most bullet cameras come with a fixed 4mm lens that allows a 70 degree angle of view. This is the widest angle you can have without distorting the picture. A 4mm lens will allow you to see facial features out to about 35 feet. If infrared is included you can generally see 35 feet minimum with no external lighting, some can see up to 70 feet.
Some devices capture images in color which is best for daytime lighting. For nighttime viewing choosing an infrared camera, which captures images in black and white is better. Many of the products will display color during the day and automatically switch to black and white infrared viewing when light levels are low. Resolution levels for black and white are usually about 400 lines, any higher resolution and the benefits are minimal. For color, the higher resolution the better the picture. Used in closed circuit television applications, bullet cameras contain essentially the same electronic components as c-mount cameras but have been modified to fit in a weatherproof casing for outdoor use. You can see from the image that some models allow the housing to be removed for installation indoors. Mounting brackets are included with each item. They can be installed on the ceiling or the wall. Voltage is 12V DC. Power adaptors are included with every camera.
The advantage to a c-mount camera is that the lens can be changed. If you need to see further than 35 or 40 ft then you’ll need a c-mount camera with a special lens. C-Mount lenses are available from 4mm to 100mm. A 4mm lens provides facial detail and a 70 degree angle of view focused up to about 35 ft. An example of where you might use a fixed 4mm lens is in a small office, or at home to focus on your driveway.
A higher millimeter lens will provide further distance, but narrows the field of view. So, a 16mm lens would provide about a 15 to 20 degree angle of view at a focus distance of about 35 ft (or a 70 degree angle of view at about 140 feet). In general, a 8mm lens is like a 4mm lens zoomed in 2 times. Similarly, a 16mm lens is like the 4mm lens zoomed in 4 times.
Many times, the best option is to use a varifocal lens. This will allow you to vary the focus from 5 to 50mm. So when you install the camera you can fine tune the focal distance and angle of view. An example of where you might use a varifocal lens is outside (or inside) a large commercial building where you need more distance than 35 ft. and the varifocal lens will allow you to adjust the focal distance to your preference.
If you want to use cmount cameras outside, you must put them in an outdoor camera housing. CCTV lenses are available in two different lens mounts. “C-mount” lenses have a flange back distance of 17.5mm; “CS-mount” lenses have a flange back distance of 12.5mm. The flange back distance is the distance from the flange of the lens (beginning of the lens mount) to the focal plane. All of the C-Mount cameras we sell can be adjusted for installation of a CS-Mount lens as well as a C-Mount lens.
Maintenance of your CCTV system is vital to ensure the effectiveness of your security camera system. The type of maintenance required varies depending on whether you have an analog video system or a digital video system. The most common problem for analog systems is the degradation of the videotapes. All too often this problem isn’t recognized until a problem occurs and the tape is unusable. When a videotape degrades the picture becomes grainy and blurry – this can make it impossible to make out important details.
The effective life of a videotape depends on the time-lapse speed of the VCR. A general rule of thumb is to take the number 2000 and divide that by the speed of the recorder. For example, if the recorder is set to tape in 96-hour mode, then the videotape will start to degrade after only 20 uses. And the VCR itself should be overhauled every 10,000 hours. This is precisely why many business owners are switching to digital video recorders (DVR) instead of VCRs. Since digital video recorders have very few moving parts they require less maintenance than a VCR. Also when there is a problem with the DVR it is usually more evident. For example, the system will start crashing a lot or it will stop working altogether. Cameras can go bad over time as well. But again, these problems are usually fairly evident. Periodically take the time to review all of your cameras and make sure that the picture on each one is crisp and clear.
Experts say that the biggest problem with many security camera systems is that they are not well enough designed to begin with. Many times a business owner is so concerned with cost that they cut corners on their camera installation. As a result there may not be enough cameras used or they might not be the right kind of cameras or lenses. Your camera system should cover all of the vulnerable or important areas of your site. Don’t overextend the camera by using lenses with a field of view that is too wide. Test out your cameras and recording equipment to ensure that it is effective for identification – not just verification that someone is there. If nighttime or low light is an issue make sure your infrared cameras are up to the task. Take few moments to ensure that your camera system is designed and working properly today – you’ll be glad you did if you ever are in the situation to depend on it!
What features should I look for in a CCTV Digital Video Recorder (DVR)?
There are several factors that are critical to consider when purchasing a DVR, especially when comparing price. The most important factors to look at are the number of cameras supported, frames per second (fps), compression technology, hard drive space, network connection / remote viewing capability, motion detection, scheduling, and ability to save video and audio to a CD or flash drive. You should also look for easy and comprehensive search capabilities (check out our ‘Smart Search’ technology) and audio support. The setup and user interface should be intuitive and easy to operate.
What is frames per second?
The frames per second (fps) relates to how many pictures the DVR will record in a second. Real time recording is about 30 fps on each camera. To calculate the fps per camera take the total fps in the system and divide it by the number of video inputs. For example, a 60 fps digital video recorder with 4 video inputs would result in about 15 fps per camera. The technology has finally gotten to the point now where real time recording is affordable. If you are recording cash registers or something similar then you should definitely invest in real time recording.
How big a hard drive do I need?
The amount of hard drive space is very important because it will limit how many days of recording you can store before the system has to start recording over the oldest video. Each DVR will have its storage capacity listed in the specifications. But this calculation is just a rough estimate as there are many factors that affect hard drive use. The most critical factor being the compression format used by the DVR (for more info on compression formats click here). But also the type of cameras that are connected to the DVR make a difference (specifically the chip size and resolution) and also the features that are selected on the DVR. If you use the scheduling or motion detection features or tune down the frame rate that will extend the storage capacity of the unit. Even the field of view (what you are recording) will affect the storage capacity – the more complex the image, the more hard drive space it will take to capture the complexity.
What is the difference between a PC-based DVR and an Embedded DVR?
A PC-based digital video recorder is basically a personal computer that has been modified with hardware and software to work as a DVR. An embedded digital video recorder is a machine that has been manufactured specifically to work as a DVR. In embedded DVRs there is typically one circuit board with software burned into the chip. There used to be significant differences in features between the PC-based and the embedded machines. But with recent advancements in the embedded DVR technologies the differences are becoming less. The advantages of an embedded digital video recorder is that they are extremely stable and reliable since they contain fewer parts. The software is often written in basic machine code or Linux code which tends to be more stable than Windows software. The advantages of the PC-based digital video recorders is that they are easier to interact with because you use the on-screen menus and a mouse (as opposed to embedded which you interact with more like a VCR – via buttons). And you tend to have more features and options on the PC-based machines.
How does a CCTV digital video recorder work?
A CCTV digital video recorder (or “DVR” for short) is essentially a computer that saves security video images to a hard drive. Most security cameras in use today capture an analog picture. The DVR converts the analog signal to digital and then compresses it.
Many cameras can be connected to one DVR. DVRs generally come with 4, 8, 16, or 32 camera inputs. The DVR will allow you to view all of these images at once or one at a time, and all of the video is saved to the hard drive. Additional switches, quads, or multiplexers are not required.
Are security digital video recorders hard to install?
Not at all. You simply plug the cameras into the back of the unit. For the PC-based: Plug in the power, monitor, keyboard and mouse – just like a regular computer. You will receive instructions on how to set up the machine with your shipment.
What comes with the DVR?
Most of our DVRs come standard with an 120 gig hard drive (unless otherwise noted). They also include the software (for setup, local, and remote viewing), power cord, and documentation. PC-based machines also come with the mouse and keyboard. You just need to add the cameras, whatever cable you need, and a monitor. For embedded machines you can use a TV set or security monitor. For PC-based machines you need a standard computer monitor. Also, we have on-site technical support available at no additional cost.
Why doesn’t the computer monitor come with the PC-based Digital Video Recorders?
We don’t supply the computer monitor with the DVR because frankly you can get one cheaper and easier locally. Large computer stores such as Best Buy or CompUSA sell these monitors practically at cost. And due to thier heavy weight, they are very expensive to ship (and subject to damage). Also, we found that many of our customers have spare computer monitors available.
How do I see pictures from a remote site?
You can view the camera video over the internet using a modem which is slow but can display 1 or 2 frames every 5 seconds. Better is a DSL or cable modem connection which can generally display 1 frame per second. When viewing remotely, the refresh rate is restricted by the communications medium (your internet connection speed). When viewing or playing back locally, the display is dependent of the unit’s frame rate (fps). You will need a static ip address available to assign to the DVR (more about this in your documentation).
What is ‘Smart Search’?
Our PC-based DVRs come standard with smart search capability. This allows you to highlight one area of a captured image and look for changes just to that area. For example, if an item is stolen off of a counter… you can go to a moment in the video where the item is still on the counter, then highlight the area around the item and search automatically through the video for the moment in time when that particular area changes, that is precisely when the item is removed and then view that part of the video. Pretty slick!
The dome camera is obviously named for its dome shape. Everyone has seen these security cameras in businesses and stores. Because of its shape, its difficult to tell exactly where the camera is aiming unless you see it up close. Dome cameras are generally used inside buildings, although the armor domes can be used outside as well (more about the armor dome below). You can mount them on the ceiling or on a wall. They are available in black and white (b/w) and color, and the basic unit has good video resolution (400 lines for b/w, 380 for color). Security Cameras.
Which type of Security Camera should I use?
A security camera can come in many different styles including dome, bullet, infrared and c-mount. The security camera that will work best for your application will depend on several factors such as whether you will use the security cameras inside or out, during the day, nighttime, or both.
Bullet style security cameras are the most popular. They can be used inside or out. These security cameras come in black and white or color and come with all of the required mounting hardware. The security camera casings are weather resistant and don’t require added external protection. Most security cameras have a fixed 4mm lens that allows you to see facial features out to about 35 feet and provides a 70 degree angle of view. This is the widest angle you can have without distorting the picture. Click here for more information about bullet security cameras.
Resolution levels for black and white security cameras are about 400 lines, any higher and the benefits are minimal. For color cameras, the higher the resolution the better.
Infrared security cameras are also very popular as they allow an image to be seen in little or no lighting conditions. Most infrared security cameras are bullet style and can be used inside or out. The cameras have infrared lighting installed around the outer edge of the lens which allows the security camera to see in no light for up to 25 feet – even further with a little bit of light (like street lighting or an outside light.) Click here for more information about infrared security cameras.
A relatively new type of security camera to the market is the day / night security camera. These types of security cameras have an extra sensitive imaging chip which allows it to capture a good picture in low light situations without using infrared leds. This is especially handy in outdoor applications because infrared security cameras do not do well in outdoor housings. Unless the infrared security camera is installed flush up to the glass of the housing, the infrared lights can reflect off of the glass of the housing which degrades the image.
The advantage to c-mount security cameras is that the lens can be changed. You’ll want a special camera lens if you need to see further than 35 ft. The color c-mount security camera allows you to change lenses on the camera giving you the ability to zoom into a particular area. Varifocal camera lenses allow you to adjust the focus from 5 to 50 mm. These lenses can be used inside only unless you put it in special housing for outdoor use. Click here for more details about C-Mount security cameras or Security Camera Lenses.
Dome security cameras basically provide a different look. Also, if you have any concerns about tampering, check out our Infrared Armor Dome Security Camera. It will withstand a 10 lb sledgehammer blow and can be used inside or out, daytime or nighttime. Click here for more facts about dome security cameras.
Which Security Camera Lens Should I Use?
How far you need to see will determine what security camera lens you should use to best fit your application. A 4mm lens will give a 70 degree angle of view with 35 feet of facial detail. This works great for residential or small office security camera applications. If you need to see further you would go with a higher powered lens. Keep in mind that the further you want to see will narrow the field of view of your picture.
A rule of thumb is that a 8mm lens is like a 4mm lens zoomed in 2 times. Similarly, a 16mm lens is like the 4mm lens zoomed in 4 times. For example, a 16mm lens would give you about a 15 degree angle of view focused at 35 ft.
What If I Do Not Know Exactly How Far I Need To See?
Instead of going with a fixed focus lens you can go with a varifocal lens. With a simple adjustment you can manually zoom in or zoom out and focus the camera to the exact distance needed to get a clear picture. Varifocal lenses come in all different sizes: (3.5-8mm; 9-22mm; and 5-50mm) just to name a few. This is the best option for large commercial applications because you can adjust the focal distance to what works just right.
What is a PTZ camera?
A Pan Tilt Zoom camera (PTZ) allows you to pan (back and forth), tilt (up and down), and zoom (focus in and out) your camera remotely. The PTZ is controlled using a remote PTZ controller or you can control it through most DVRs (look for PTZ support). The disadvantages of a PTZ camera is that they are very expensive (usually around $1000 without the controller). And all the moving parts make it susceptible to wear and breakdown. There are some new digital versions of PTZ cameras just coming on the market that have no mechanical parts. These PTZs are very promising but are still a little too expensive to be practical for most uses. PTZ cameras require a data cable to be run to the camera in addition to the video and power cables. Unless you have a person who is watching the scene and adjusting the field of view of the camera based on what’s going on its not as useful. Most times you are better off buying more of the non-PTZ cameras to continuously cover the area rather than a PTZ.
What is the difference between no iris and auto iris?
The iris controls how much light is let into the camera lens. In the old days, cameras came with no iris control. If you needed to control the light levels you would have to purchase a special lens. Nowadays, most cameras come with automatic shutters which perform the same function as the iris – controlling how much light is let into the camera. Unless you have an application with extreme light levels (like at a beach) you probably won’t need a special lens with iris control.
|bandwidth||Its popular meaning refers to the amount of data that can be transmitted per second over a wire or network. When it comes to video surveillance applications you need a high amount of bandwidth to transmit the large files. For remote viewing, 56K modems will not work well. DHL is OK, and cable modems or T1s (or better) are best. And you also want the best video compression you can afford to make the files as small as possible.|
|CIF||Common Intermediate Format – a set of resolution standards used in video applications, defined as follows:
|CODEC (aka “Code-Decode” or “Compression-Decompression”)||A term referring to any technology used to compress and decompress large files such as audio and video files for efficient data transfer.|
|compression standard (or compression algorithm)||A standard approach or ‘formula’ for compressing (and decompressing) data (in our case, video and audio data). There are many standard image or video compression algorithms available today (many are described below) and new ones come out each year.|
|D1||D1 is a video resolution standard. In NTSC it is 720 x 480 pixels. Its affect on video compression and transmission is due to the fact that the excellent resolution of a D1 image produces larger files to be compressed and transferred.|
|H.264 Compression (aka MPEG4+ or
MPEG4-Part 10 or AVC (Advanced Video Coding))
|The latest MPEG4 compression technology, released in 2003. H.264 provides excellent video compression. You get the same quality image as MPEG4 even at the higher resolutions like full screen D1.|
|ISO (aka International Organization for Standardization)||ISO is an international organization founded in 1946 that organized and reviews standards worldwide. Their members such as ANSI (American National Standards Institute) and OSI (Open Systems Interconnection) create the standards and they review them for completeness and other criteria. ISO is not an acronym; the name derives from the Greek word iso, which means equal.|
|lossy compression||Sometimes a compression algorithm will lose some detail of the original image in its compression of that image. An algorithm that loses some detail of the original image is called a ‘lossy compression’ algorithm. JPEG, for example, is considered to be a ‘lossy’ compression.|
|NTSC||National Television Standards Committee – the analog video representation standard used in the US and South America. Compare to PAL.|
|PAL||Phase Alternating Line – the analog video representation standard used in Australia, and most of Europe and Asia. Compare to NTSC.|
(aka Joint Photographic Experts Group)
|A standard format for image compression (defined by the group who gave it its name) It was first introduced around 1986 and is a very common image format used on the web. JPEG is only used for photo (single frame) images (not video). JPEG is a ‘lossy’ image format – some of the detail of the image may be lost in its compression.|
|MPEG compression (aka M-JPEG or
“Moving Picture Experts Group”)
|A standard format for video compression first introduced around 1988. MPEG achieves high compression rate by storing only the changes from one frame to another, instead of each entire frame. Although MPEG is lossy compression, the loss of image detail is generally imperceptible to the human eye except at the highest resolutions.|
MPEG has gone through several revisions as follows:
MPEG4 compression (aka MPEG-4 or H.263)MPEG4 was standardized in 1998 by the ISO and combines MPEG-2 and Apple’s QuickTime technology. This resulted in a nice clear picture but also compressed much better than previous technologies.MPEG4+ compression (aka H.264)The latest MPEG4 video compression technology. See H.264 compression for more information.proprietary compression algorithmThis refers to a compression algorithm that does not follow one of the compression standards such as MPEG4. Many times a proprietary algorithm will follow a standard mostly but then tweak it in some specific way. The result may be a better (more efficient or better quality) compression but the downside is that since it uses a proprietary formula it may not be compatible with other products. Many DVRs and IP systems will use a proprietary algorithm within their product (for example to store the images to the hard drive) but provide interfaces in standard formats to communicate with other systems (for example when backing up a particular video event to a DVD).Resolution (or Resolution Standard)Resolution is a measurement of the quality or level of detail of an image. Usually expressed in terms of pixels, dots, or lines per inch. CIF and D1 are examples of some standard resolutions. The higher the resolution is, the greater the detail and number of pixels in the image will be, and also the larger the resulting video file will be.Run Length Encoding (RLE)This is a very simple form of data compression in which sequences of the same data value which occurs in many consecutive data elements are stored as a single data value and count, rather than as the original sequence.
Surveillance is more than just mounting cameras. No two clients have the same surveillance needs. We specialize in designing systems that are industry specific, and scalable to fit your company as you grow. A video surveillance solution can help you better deter theft, detect fraudulent liability claims and document events, so that your entire business can be better protected. It is also a tool you can use to help improve employee productivity and help them become more efficient.