Saturday, April 20

Video surveillance security camera: buying guide

Are you looking for a video surveillance security camera? Here is a simple buying guide to find out a little about the possibilities you have in this regard!

Having to buy one or more cameras to compose a video surveillance kit, it is essential to clarify what your needs are and start from those and then find the solution that best suits your needs. The first thing is to understand what is required of your video surveillance security systems in Chicago and determine if you need to monitor a place, check an event, or identify individual people or objects and, moreover, try to understand what type of quality is required by the acquired images. In fact, the characteristics of the systems vary greatly according to the function they perform, if they are used for simple monitoring, for detection, for recognition of known people or for identification of strangers, for plate detection, for counting or for quality control

How to choose video surveillance security cameras?

Video surveillance cameras are distinguished by their shape, technology and functions.

As a shape you can choose the PTZs that move both horizontally and vertically, can rotate 360 ​​°, enlarge and reduce the images (hence Pan Tilt Zoom, the meaning of PTZ).

Bullet cameras are practically the stereotype of video surveillance security cameras and are in effect a must. So called because of their “bullet” shape, they are suitable for both full and external shots and are very resistant as well as ideal for covering long distances. The advantages are great adaptability, versatility and resistance and are more suitable for corners and walls as they are elongated; while among the disadvantages we can point out the meticulousness with which they must be placed being careful to different factors that can negatively influence the quality of the recovery, such as reflective surfaces, opening of windows and doors that can obscure them, the LEDs that can “blind”, especially in Closed places.

The Dome or Mini dome, or Eyeball depending on the model, instead, have a hemispherical shape, are covered by a glass dome (not the Eyeballs) and are suitable for being positioned on the ceiling, but can also be placed in parades. Of this type of cameras there are also models with wide visions (fisheye) that reach viewing angles of up to 180 ° thus managing to frame the entire area. They are often preferred for indoor solutions, as they are more discreet and aesthetically suitable for indoor installations, sometimes the indoor versions also have the microphone on board to perform ambient audio recording.

The technologies of the cameras

Technologically, we distinguish between analog and digital cameras. The analog cameras with Pal coding, have a resolution expressed in TVL (TV line that is the number of lines that make up the images) that goes from 280 to over 1000 TVL, but be careful the PAL analog signal by its nature is not able to ” perceive”more than 768 × 576 lines, then brought to 960 × 576 with some recent changes. So cameras with resolutions higher than 1000 lines, on analog in fact allow the acquisition of a good source, but then reduced due to the analog technology in recording.

Other technologies have recently come out that allow a video signal to be transmitted with the same technical principles but bringing the resolution up to 2 Megapixels (1920 × 1080) so as to allow the same old infrastructures and with really reduced upgrade costs.

These technologies are AHD, HDCVI and HDTVI, technologies that have often been tackled, now highly mature, for our part we consider AHD and HDCVI to be the most reliable and technically most advanced products for sure, but the market will judge them. definitive.

Finally we have digital technology over IP, here there are other very different scenarios depending on the applications, in reality there are NO real limits of resolutions, it is only a question of portfolio and needs, there are cameras with resolutions up to 24Megapixel today, and also cameras that aggregate multiple sensors into a single 360 ​​° image, you need to understand the need and find the most suitable path.

But what is the right resolution for you? There are interesting calculators that allow you to understand the differences with the various cameras, but in principle we can say that up to 5- 10 meters we have every detail even with analog cameras, besides it is necessary to understand what the needs are and move on to different technologies, but this is a topic that deserves further information that you can find here in another article of our blog.

The important functions that must be taken into account before purchasing are numerous

The visual field, that is the width of the frame: a shorter focal length has a greater visual field. Also in this case, at this link , you will find an in-depth analysis with an article entirely dedicated on how to evaluate the cameras based on the shooting point.

The sensitivity, ie the need for a minimum illumination. If you plan to position the cameras in semi-dark areas or with a strong contrast (very bright areas with areas without lighting) it is important to inquire if the camera has useful features for use in these environments (sensup, WDR, zero light, etc) technologies which help to manage critical lighting situations, usually present on medium or high-end cameras.

The presence of LEDs for night lighting and their power, in addition to the type of LED (less powerful LEDs usually give better light conditions) or technologies such as the “Smart-IR” that allows an automatic adaptation of the IR with respect to the framed subject (reduce the power if the subject is close and increase it if it is far away)

It is also possible to use separate IR illuminators which usually guarantee a more powerful light and from a separate source compared to the camera, which guarantees a sharper image (exactly as for professional photos we use flashes remotely compared to the camera)

In addition, resistance to temperature changes and weight are characteristics to be taken into due consideration especially where the external temperature can be very high (above 50 °) or very low (strongly below zero) in these cases, optics, LEDs, electronics are very stressed and the results can affect the images, losing sharpness or quality.

The more professional cameras in addition to having high resolutions, are equipped with advanced features such as anti-glare adjustment for clear recordings even in the presence of car headlights (Eclipse) or the WDR function that eliminates the backlight problem are just some of the technologies present , carefully evaluate these aspects, especially if the installation involves critical issues (roads, long distances, high height, presence of objects, tunnels, etc.)

Finally, we must not forget that the final quality of the images depends both on the technical peculiarities of the camera and on the quality of the recording as well as the infrastructure (cables and power supplies). For the purpose of viewing and eventual identification, the quality of the images seen live is not as important as that of the recorded images, therefore it will be necessary to also take into account the quality of the DVR and what is necessary to bring the signal to it. 2 megapixel images, but recording them at a lower resolution, or at a reduced speed (Frame Per Second) would make me lose many of the peculiarities of the camera.

With this smart camera it will be easier to consult the shop and choose the video surveillance security cameras in Chicago that best suits your needs, request a quote now!