Security solutions have a place in any industry. From education to healthcare, retail to gaming, finance to manufacturing, every market has a unique need for securing their premises. The surveillance needs for each market can result in one of many different solutions available, so it is important to understand what each product is offering.
To find the solution that is best for your security needs, it is essential to be able to identify what resolution, body styling, special features, environmental features, standards & compliance, information compression, and to have a knowledge of lenses, among much more. In this article, Accu-Tech seeks to break down the different parts of buying a camera so that it is easy enough for anyone to understand.
Resolution - This term refers to the quality of picture a camera receives, based upon the smallest units of measure. There are pixels for digital cameras, or television lines for analog cameras. Also, pixels can be described in two different terms: horizontally x vertically, or the total number of pixels present. Therefore, a camera with a 3648 x 2741 resolution, and a 10 megapixel camera are offering just about the same amount of pixels.
Higher resolution cameras are usually used to recognize faces or license plates, whereas lower resolution cameras are typically used to get an idea of what is happening over a larger area. When designing a camera system, minimum resolution requirements for different areas and applications often refer to pixels per foot (PPF) to get initial estimates.
Body Style - The two main body styles in use with security cameras can be broken down into th dome and bullet styles. Both have pros and cons, and really depend on what your specific use is going to be.
The dome stlye is quite vandal-resistant, as the bubble is usually made from polycarbonate or acrylic materials, alongside a sturdy metal frame. In addition to these materials being quite sturdy, the bubbles also provide glare resistance. The smaller profile makes it a much more difficult solution for vandals to attack. These styles, however, suffer from limited mobility and fields of view.
A bullet style camera is fairly opposite from a dome style. They offer flexibility and maneuverability, but those benefits put the style at risk. If bullet cameras are placed closer to the ground, they are susceptible to spray paint, smashing's, or even a simple change of position.
Features - Cameras can have many additional features, depending on the brand, make and model. Some features that are commonly added include color only, day & night modes, auto-iris, infrared built-in, and wide dynamic range (WDR). These are all fairly self explanatory, and as this article is meant to give an overview, will not be discussed here. It is good to keep in mind that piling on features will dramatically increase your systems functionality, it will also balloon final cost, and increase how much information will be traveling across the system infrastructure.
Environmental Features - Apart from being vadal resistant, or specifying indoor/outdoor, an additional consideration is the IP Code, or the ingress protection rating. The ingress protection rating rates the degree to which the mechanical/electrical casing can protect from intrusion, dust, liquids, accidental contact, and more. The north american enclosure rating systems are defined in NEMA 250, UL 50, UL 508 & CSA C22.2. The IP Codes are (from lowest rating to highest): IP20, IP54, IP66, IP67 & IP 68
Lens Options - Lenses can be purchased together with domes and cameras, or separately. The lens affect the cameras viewing angle, focal length and the viewing distance.
Compression - Compression technologies have been undergoing steady evolution as recording and storage systems have improved. Analog cameras record through a central digital video recorder (DVR), and video compression is performed there. IP camera's compress first, and then transmit data to the network video recorder (NVR). There are a variety of compression technologies available, but no clear standard. Frame by frame compression result in a series of individual images, and is often captured with JPEG or JPEG2000 formats. Inter-frame compression utilizes MPEG-4 or H.264 formats, and works by compressing data into one frame and analyzing what changes between the frames.
Binning - Binning is the process of taking groups of pixels and combining them into a single pixel. Standard binning occurs before analog to digital conversion, and adds the analog charges from two or more pixels then averaging them to create a single pixel value. Subsampling is similar to standard binning, the difference being that the process occurs after analog to digital conversion occurs. Decimation is when pixels are combined and certain pixel values are simply discarded.
Standards - The two standards that dominate the security camera industry are PSIA (Physical Security Interoperability Alliance) and ONVIF (Open Network Video Interface Forum). Compatibility issies can be found between devices across the formatting division, so it is important to research which format has products and services that are most relavant to what you are trying to accomplish in your security setup. In recent years, ONVIF had started to dominate the market, but Microsoft has just joined the PSIA standard in September, 2013, so expect the market to swing back towards PSIA.
There are many other factors that come into play when deciding on a security system. Additional terms and features that may want to be researched include: motion detection (zones per sensor), multi-streaming, pixels per foot (PPF), regulatory approvals (concerning FCC, CE, UL), and compliance (WEEE, RoHS, REACH)
Arecont Vision has simplified this process even further by creating their Product Selector page, which breaks down the above mentioned characteristics into an easy to use product sifter. Sift through over 270 security cameras, with the ability to compare up to 5 at a time to see which is right for your security solution.
To learn more about Arecont Vision cameras, contact your local Accu-Tech representative today, here.