How to choose an IP surveillance camera
29 august 2019
Based on what we reviewed earlier, surveillance through an IP camera, in our opinion, is the most advanced and functional way than analog systems. Therefore, in this article, we will consider only the practical points in which IP-camera to choose for the home, and which for the street.
Lens selection and focal length adjustment
Monofocal, varifocal and zoom. don’t be intimidated by THESE words, they will help if you don’t know which lens to choose for a surveillance camera.
The monofocal view of the lens has a certain focal length and a certain angle of view. it is simply impossible to change these parameters. Cameras with such lenses are inexpensive and easy to use. If you don’t need to rotate and drag the camera, this option is fine. Configurable and controllable IP cameras are equIPped with varifocal and zoom lenses, with the difference that the latter can be adjusted remotely using the remote control. Focus and zoom functions are very handy when adjusting the coverage of the recording area, especially if you need to periodically adjust.
It is not difficult to distinguish between the types of lenses. In the case of fixed shooting, the specifications will indicate a specific focal length, for example, 2.8 mm. In the second cases, the adjustment range is indicated. 4.8-120 mm. Remote control lenses are used in mechanical PTZ cameras, in which we will say below.
To correctly select the focus of the surveillance camera, use the table for converting viewing angles to focal length:
|Focal length||1/3 “dies||1/4 “dies|
|Horizontal viewing angle||Vertical viewing angle||Horizontal viewing angle||Vertical viewing angle|
In other words, the function of night shooting. If there are LEDs around the lens, then the camera is equIPped with infrared illumination, which means it is capable of recording in the dark. The more LEDs, the better the picture quality.
Recording with sound
If your surveillance requires more than just the image, choose cameras with sound recording. Microphone and speaker can be either integrated inside the device or connected externally (usually cameras have a bi-directional audio channel for this).
Features. Basic Guide
The main technical characteristics of an IP surveillance camera are what you should focus on first. The basic ones are worth highlighting:
- Matrix type and resolution;
- Optics quality. lens;
- Frame rate;
- Housing (for choosing an outdoor surveillance camera).
This function saves a lot of storage space, as it allows you to configure the recording only when moving in the frame. A useful addition can be a notification about the start of shooting on your device, to monitor the situation when necessary.
Which matrix is better to choose a camera
Studying the technical descrIPtion of IP cameras, you can find two abbreviations related to the matrix: CCD or CMOS. The latter are more common (especially in inexpensive models), have low power consumption and high performance, and are also distinguished by better shooting of bright objects. The main advantages of CCD-matrices: good light sensitivity and better perception of moving objects, due to which they are especially distinguished when buying car cameras.
Not without reason, more attention when choosing any camera falls on the resolution of the matrix. Do not look at the fact that 1.3 Mp will be enough for simple home cameras, we recommend choosing cameras for surveillance with a resolution of at least 2 Mp.
|SXGA||1.3||1280 × 1024|
|WUXGA||2,3||1920 × 1200|
|QXGA||3.1||2048 × 1536|
|WQXGA||4.1||2560 × 1600|
|QSXGA||5.2||2560 × 2048|
The more pixels in the matrix of an IP-camera, the more it will capture small objects, which directly affects the image quality. But at the same time, multi-pixel shooting will weigh accordingly. Take this into account when storing your archive.
Useful IP Surveillance Features
In addition to the main technical characteristics, auxiliary functionality is also provided for surveillance cameras. They choose IP-cameras with the presence of certain functions, exclusively according to their needs. And, of course, the more features and the better they are, the more expensive the equIPment will be.
Box cameras. what to watch out for
When asked how to choose a surveillance camera for the street, we will answer: yes, like any other, paying attention to the same parameters (matrix, focus, resolution, etc.), I added the characteristics of the case to them. The point is that the optics and electronics of the equIPment will NOT survive the harsh weather conditions without a good outer shell. Therefore, outdoor cameras are equIPped with heating, dust and moisture protection and, often, anti-vandal systems.
For outdoor IP cameras there is another IP, only Ingress Protection, which means the degree of protection of the electronics from water and foreign particles. For example, the designation IP10 indicates that the device is protected from the ingress of small particles and is NOT at all protected from moisture, while IP68 indicates the complete dust and water resistance of the device. For case IP surveillance cameras, it is desirable that the IP degree is NOT lower than 54.
How to choose a surveillance camera: varieties, models, characteristics
In order for the purchase to be successful and the installed system to function for a long time and efficiently, he will try to figure out which camera characteristics are worth Paying Close attention.
Lighting conditions and device sensitivity
The second important aspect is the lighting conditions, the efficiency of your surveillance system will largely depend on it.
High sensitivity is needed where there is not enough light, for example, at night outdoors with no lights or indoors without windows.
An additional plus will be the presence of an IR filter or infrared illumination. The human eye is NOT able to perceive infrared radiation, however, these devices fix it very well.
Some of them can see in near total darkness. In SEPARATE cases, the best solution would be to install an additional IR illuminator, they are chosen according to the illumination range, viewing angle and power.
The camera’s sensitivity corresponds to the minimum illumination level at which it will function effectively. This parameter is always indicated in the characteristics, it is measured in Lux (lx, lk), the brighter the lighting, the higher it is.
Before choosing an outdoor surveillance camera for 24/7 operation, please make sure its sensitivity is 0.01 lux.
Approximate Illumination Levels Under Certain Conditions:
Daylight on a sunny day outdoors. 5000. 100000 lux;
Daylight in cloudy weather. 4000. 5000 lux;
Deep twilight. 1.0 lux;
At night outdoors under the moon, in the absence of additional lighting. 0.1. 0.3 lux;
On a moonless night. 0.01 lux;
In parking lots. 30.75 lux;
Office premises and warehouses. 50. 500 lux;
On well-lit highways at night. 10.00 lux.
Modern compact cameras are capable of capturing very high quality images. Read more here, these and other spy devices.
Worried about the safety of your summer cottage? Find out on this link about the features of surveillance kits for summer cottages.
Typically, the lighting at the facility changes several times during the day. Auto iris lens or built-in electronic shutter helps keep the amount of light entering the sensor at a constant level.
These functions allow you to receive a signal of high contrast, without blackout and flare.
Auto iris models are used in varying lighting conditions where maximum depth of field is required for detailing the edges of bright objects.
Color or black and white?
Using a color camera will help Get much more information and a realistic picture.
In some cases, a color image is necessary, for example, if you need to determine the color of a car or a person’s clothes. At the same time, it needs more light for normal operation.
With its lack, characteristic noise appears in the color image.
Many manufacturers have solved this problem, equIPped their devices with a day-night function, in which, in low light conditions, it automatically switches from color mode to black and white.
While all characteristics are similar, monochrome products are much cheaper than color ones, but the price difference is constantly decreasing.
It is worth noting that a number of the latest developments have found their widespread use only in color cameras, for example, such functions as backlight compensation (BLC) or wide dynamic range (WDR).
Camera resolution and image quality
The higher the camera resolution, the better the image quality.
High-resolution cameras are needed where detailed information is important or surveillance is carried out from a long distance.
It should be borne in mind that a stationary recorder, multIPlexer, server and all other equIPment must also support high resolution. Otherwise, an expensive model will not be able to show all its capabilities, and its work will not differ from the budget one.
All monochrome cameras are conventionally divided into high resolution models (550-570 TV lines), medium (380-420) and low (up to 400 TV lines).
Installation site. Street or premises?
Before proceeding with the selection and deciding which camera to choose for surveillance, determine the location of its installation
If you need an outdoor surveillance camera, then pay attention to the temperature mode of operation.
Sealed housing and heating system will allow it to function in harsh outdoor conditions.
And for outdoor surveillance, it is better to install a full-fledged stationary camera. Read here about the advantages and disadvantages of wireless outdoor surveillance cameras.
If high humidity is expected, for example, the device is needed for a car wash, then you should take into account such a parameter as humidity and choose a device in a moisture-proof design.
For installation, it is best to choose a location that is out of reach. If there is a possibility that the camera can be damaged by someone, for example, it is not high on the street, take a closer look at the devices in the anti-vandal case.
Remember that even reliably protected equIPment will not last long against an intruder with a hammer, so it is better to choose an installation location where no one can damage it.
Focal length and viewing angle
The overall view of the image (Portrait, Panoramic or Medium-Close) depends on the focal length of the lens, it is this that determines the angle of view.
The angle of view depends on which lens is attached.
Choosing a camera for monitoring with a variable angle of view will allow you to manually adjust the angle and angle of view at any time, which is undoubtedly convenient. However, such devices are more expensive than those equIPped with a fixed lens.
With a larger viewing angle, the effect of distancing occurs, less details can be disassembled. The smaller the angle, the more detailed information you can capture.
For example, with a small viewing angle, you can see people entering the room in detail, but you will NOT be able to see the whole room. If you need to cover the entire room as a whole, choose a device with a viewing angle of 90º.
To observe objects that will be located at a distance of 30-40 meters, you need a device with a viewing angle of no more than 45º.
Sometimes, to improve security, it is enough to install dummy cameras. Find out at this address how to properly install a dummy dome camera so that it looks like a real one.
Convenient if a surveillance camera transmits a signal via a wireless interface. Read in this publication how to choose an IP surveillance camera with Wi-Fi for your specific needs.
Selecting a surveillance camera is not an easy task, it is necessary to clearly formulate the requirements for the equIPment, and take into account many parameters, some of which can change during the day.
If you DO NOT doubt your abilities, the best solution would be to seek help from professionals in the field of surveillance systems, they will help you carry out all the necessary calculations and make a choice.
Otherwise, the aperture. This parameter is needed to designate the lens aperture. If the number is low, it means that the aperture is most open and adapted for shooting in low-light situations. Consequently. The more closed the aperture, the more the lens is adapted for shooting in bright rooms. It repeats the functions of our eyes: in light, the pupils narrow, in the dark, they expand.
How to choose a lens for a surveillance camera
The lens is the most important part of a surveillance camera. It depends on him how effective your surveillance camera will be.
Lens angle of view
This parameter reports how much surface the lens will capture into the frame. If the angle is wide, then the lens is called wide angle and covers the largest area. The focal length in such lenses is less than 3.6 mm. If you are interested in the details of the shooting and the ability to consider small elements on. The angle of view should be less, and the focal length should be at least 16 mm.
Lens mount types
There are three types of them, and they all differ in the distance from the extreme point of the lens to the matrix.
- Mount type C. 17.5 mm. Compatible with CS mount via adapter.
- CS mount. 12.5 mm. Incompatible with C.
- M12. 12 mm.
In fact, focal distance is called the gap between the end point of the lens and the matrix on which the image is focused. The standard focus distance for residential or office cameras is 3.6mm.
The higher the focal length, the sharper the image you will get at the output, but the coverage area will be less. If the focusing distance is shorter, details will not be as clear, but you will be able to observe a large area. For example, for parking.
The larger the matrix, the more space it “sees”. Therefore, the smaller its size, the less coverage you will get during observation.
Types of lenses
- Monofocal. These are fixed lenses, the value of the focal length in them is unchanged. You will NOT be able to change the angle of view or focus on the desired object of observation. Their plus is an affordable price.
- Varifocal. With such lenses, you can easily adjust the focal length and change the angle of view. However, you will have to do all these steps manually when setting up a surveillance camera.
- Lenses with zoom (approximation) function. In these lenses, the zoom function is added to the focusing and angle of view functions. Most often used in surveillance cameras that can be accessed remotely.
Next, we’ll look at what to look out for when choosing a lens.
Adjusts the amount of light entering the lens. In low-end models, the diaphragm is static and cannot automatically adjust the light level. Therefore, shooting on objects with light changes will be difficult.
Auto iris lenses are more expensive than conventional lenses, but you do not have to artificially maintain the illumination of the subject with such a lens for shooting at different light parameters.
VD \ DD parameters
- Videodrive is a type of auto iris control. In this case, the control signal comes from the image (from the camera board).
- Direct Drive. DC iris control. Then the control signal will come from the lens itself.