If you want to select a model yourself, we recommend using the general catalog with a convenient filter by parameters (from prices and brands to minimum illumination and the size of the sensor).

Purpose of the camera

The first task of a future user of a video surveillance camera is to answer the question of what it is needed for. Often these devices are bought to ensure the safety (or security) of the object. So, in apartments and offices, private homes and cottages, in stores and warehouses — cameras are usually put to prevent unauthorized entry, theft and / or vandalism. But they can also be used for monitoring: at home — for elderly people, small children, pets, in business — for their own staff and customers (visitors).

For example, if you want to prevent anyone from getting into your cottage in winter, you should install several cameras with good visibility and a motion sensor around the perimeter of the site. To control the cash register in a small store will be enough even one model, but it is important quite different factors — excellent image detail, which will allow you to consider all the actions with bills. To monitor children or elderly people is often a priority not even the quality of capture, but the availability of feedback for voice communication. And for serious military purposes (for example, guarding a military base), high-quality operation in the dark and in other conditions of poor visibility is extremely important: here another principle of operation may be useful — not optical, but thermal imaging.

We'll definitely go into more detail about the key capture parameters for different situations. But the first step after you've figured out the purpose of the model is to determine where you want to use it (indoors or outdoors) and the form factor of the body.

Choosing the place of use and camera form factor

It is logical that cameras designed for indoors are suitable for apartments and most offices. Their distinctive features, as a rule, include compact sizes and minimal requirements for body protection. For private homes, parking lots, warehouses, industrial enterprises and other facilities that require surveillance around the perimeter of buildings, outdoor models are needed. They are distinguished by their readiness for various weather surprises (heat and frost, precipitation, wind), dust and other contaminants. Many outdoor surveillance models also come with vandal-proof protection, meaning a reinforced body that can withstand impacts. Accordingly, these models tend to be more bulky and noticeable.

Home surveillance cameras are usually compact and may not be noticeable to others at all.

For many objects, two types of cameras may be needed — for outdoor and indoor use. For example, for a private house where there are children or elderly people, for a supermarket and an office center with parking.

It is worth considering that outdoor cameras are generally more versatile, because they can be placed indoors (unless their large size is not a problem). Models for indoor video surveillance is more fastidious, some even unheated warehouse or warm but dirty shop contraindicated. But today in the relevant segment there are exceptions to the rules: models that are ready for low temperatures or with decent moisture and dust protection (suitable, for example, for a catering kitchen or indoor swimming pool).

Indoor surveillance cameras

It doesn't always make sense to chase very secure cameras for the street. So, instead of high anti-vandal characteristics, sometimes you can install the model higher, and an alternative to standard water protection would be to place the device under the canopy.

Indoor cameras are usually made in a dome form factor (for mounting on the ceiling) or a small body for placement on horizontal surfaces. Among the latter, there are many portable models, which sometimes increases the versatility of use. Outdoor cameras are made in a directional (sometimes called Bullet format) or dome body. The latter are slightly smaller in size, while the former allow you to install a more complex lens, including one with an optical zoom function.

The outdoor camera is ready for challenging conditions, but, because of this it is quite bulky.

When choosing a suitable body, you should take into account the planned installation location (dome models are almost always fixed on the ceiling) and aesthetic considerations (visibility, how the device looks in the interior or on the facade, etc.).

Outdoor surveillance cameras

Why should IP cameras be considered and the issue of wires taken into account?

Analogue cameras (with BNC connection interface) today have lost their main advantages over IP models. Once they were distinguished by relatively simple setup, extremely favorable cost and widespread use of such systems (for scaling, it was inexpedient to switch to digital). Now such models have only one significant benefit — it is a long range of wiring (300+ meters) without extra charges. But, firstly, 100 meters supported by IP-cameras is enough for most conditions. Secondly, there is special network equipment for increasing distances - switches, modulators and other alternatives.

In general, it’s worth buying analogue cameras today only if you already have such a video surveillance system and need to expand it. In all other cases (you need a single camera for a child’s room or a complex security model for a large production facility), you should choose an IP model. For greater persuasiveness, here is a comparative table of two technologies (analogue and digital):

Criterion IP cameras Analogue cameras
Relevance of technology Remains Declines, it is obsolete
Range Large and growing Actively declining
Price Still higher, but leveling off Still lower
Filming quality High and free of interference Good, but not resistant to interference
Compatibility Broad, not brand specific Low, some manufacturers have their own closed standards
Connection and setup Simple Simple, but require a DVR
Data transfer With and without wire Only with wire
Maximum cable length up to 100 m more than 300 m
Additional functions Extensive, including video analytics Often missing

When choosing an IP camera, you need to be sure to consider its wiring, more specifically data transfer and power supply. At first glance, models with Wi-Fi seem to be a very tempting choice. They are often called wireless. But you need to understand that such a device still needs to be provided with power (fully autonomous models with batteries or even solar panels are rare).

Wireless data transfer is a good choice for a cottage or a distant warehouse, but in apartment buildings and large office centers, everyone has their own Wi-Fi and operating frequencies are heavily loaded, so every wall reduces signal transmission quality. Since the camera still needs to be powered, under the conditions described above, models with a wired connection via a LAN connector and the PoE function look quite interesting. Thanks to the latter, both power and video signals are transmitted over one Ethernet cable.

PoE technology in cameras can reduce the amount of wires, because both power and data can be transmitted by a single cable.

True, if the camera is installed after the renovation work has been completed in the room, then it is often easier to solve the issue of connecting to an electricity source than to a wired Internet. That is, Wi-Fi models are still preferable here.

IP cameras with PoE

Camera image parameters: deciding on the sensor and lens

One of the key points for a video surveillance camera is, of course, the shooting parameters. They depend mainly on two components — the sensor and the lens. The first directly determines detail (clarity), and the second determines visibility (space coverage), but there is also a mutual influence, that is, you should not select them without separation from each other.

When choosing a sensor, you should consider the following factors:

  • amount of megapixels. There is a simple rule: the more, the better, and below 2 MP (i.e. Full HD resolution) options should be avoided. The amount of megapixels directly affects the image clarity, i.e. the ability to see small details in the frame, including a person's face, license plate number, and other identification marks;
  • real sensor size. Not all brands explicitly state this feature, but the "bigger is better" principle applies to sensor size, impacting the amount of light and image quality in low-light conditions. A 1/4" sensor may suffice for basic use with a tight budget, but for effective night video surveillance, consider models with 1/2" or larger sensors to minimize noise in low-light situations;
  • sensor manufacturer. The buyer does not always know this information. But if you manage to take a camera with a Sony, Omnivision or ON Semiconductor sensor, it will be an additional guarantee of image quality against noname analogues with the same amount of megapixels.
The more megapixels a camera has, the more detail you can see.

In certain usage cases (for example, if you need to capture cars or fast-moving people), you should also pay attention to the frame rate. Even 15 fps is sufficient for typical video surveillance tasks, but higher values (from 25+ fps) will ensure informative display of dynamic scenes on freeze frame.

The lens determines the angles of view of video capture. It is on these parameters of optics and should be guided, if they are specified by the manufacturer. If the viewing angles are not given, then the focal length is usually given. Here there is an inverse dependence: the smaller this value, the wider the visibility will be. Thus, the most popular models today have a focal length of 2.8 mm, which provides coverage of about 100 degrees. Models with 3.6 mm give approximately 80-degree visibility, and with 6 mm — 60 degrees.

The viewing angles of the lens are inversely proportional to the focal length.

While opting for cameras with minimal focal length and a wide angle lens may seem like a convenient way to cover an entire room, it comes with trade-offs. Although these cameras provide increased visibility, they sacrifice detail and introduce noticeable distortions at the frame edges. As a result, they are more suitable for general surveillance in places like stores or offices, but for tasks requiring facial recognition or capturing fine details like banknotes, models with a longer focal length (6+ mm) are necessary.

Accordingly, the less visibility of the camera with the same amount of megapixels of the sensor, the more noticeable the details in the frame. So, with 2.8 mm lens it is good to cover a large area with observation, and with a 6 mm model it is good to examine individual sections of the frame. The latest lenses allow you to see a person's license plate or face at a greater distance from the camera. Therefore, for example, it is reasonable to install three or four devices with 2.8 mm lens around the perimeter of a private house (visibility around 100 degrees for each), but at a height in front of the entrance (gate) or nearby on a pole (overlooking a busy street) — a model by 4 or even 6 mm.

Basic recommendations for choosing a sensor are to take a model from a well-known manufacturer (if possible) with a large amount of pixels and real size. The lens is a bit more complicated:

  • for comprehensive coverage of a wide area with optimal detail, opting for a 2.8 mm lens is preferable over pursuing wide-angle variations. This lens provides good visibility without significant compromise to image quality. Additionally, considering a PTZ model is advisable in such situations. PTZ cameras, equipped with motorized controls, enable remote tilting and rotating, often accessible via smartphones. Modern PTZ cameras may support features like patrolling (non-stop movement between points) or object tracking (detecting and following movement). Alternatively, models with panoramic shooting using multiple on-board lenses are an option, but they tend to have a smaller range and higher cost compared to PTZ versions;
  • when details in the frame are important (cashier work, faces, license plates), then viewing angles need to be reduced, choosing lens with a larger focal length (up to 6 mm);
If more clarity is needed, lens with a longer focal length is required.

  • if you are going to mount the camera yourself and do not yet know the optimum ratio between visibility and detail, the models with variable focal length will allow you to select it experimentally. They also provide the possibility of optical zoom. Basic models provide 5x zoom (usually a focus of 2.7 – 13.5 mm), and advanced ones even 30x. True, the price tag here is noticeably higher than on a model with a fixed focal length;
  • when good visibility is a priority, then it is acceptable to take a camera with a wide angle lens (the picture quality will not be very high). A normal, inexpensive choice for monitoring lonely elderly relatives.
Rotating surveillance cameras

Don't forget about backlighting and light compensation technologies

Once the sensor and lens have been sorted out, you need to consider the light factor. Thus, almost any outdoor model is exposed to direct sunlight once a day (and indoors — under the influence of glare). In order to informative capture did not suffer, it is better to choose cameras with backlight compensation, including WDR or DWDR technologies. In short, they make darkened areas of the frame lighter and over-lit areas darker.

The difference in the image with and without backlight compensation is sometimes very significant.

If good performance at night is a priority, then, as mentioned earlier, you should look at models with a larger real sensor size. Also in this case, you definitely need a model with backlight. The latter may differ in range, number of diodes, as well as additional options. We recommend testing the backlight operation in practice. In some cases, its intensity is frankly weak, but it also happens that, on the contrary, it is excessive — and then nearby objects (including people) are overexposed.

More often, cameras feature infrared (IR) illumination. It is not perceived by human vision (invisible) and provides black and white filming. Recently, you can also find LED backlighting — it gives a color image, but is visible to others.

It would also be a good idea to take into account such an indicator as minimum illumination. It determines the conditions when the backlight is turned on: in some cameras it will only be needed on a cloudy night, while in others it will be needed even when there is light from a lantern nearby.

Surveillance cameras with LED backlighting

What features do modern surveillance cameras have?

If you suddenly decide to use analogue cameras, then you shouldn’t count on any advanced functionality. In the case of network models, the range of possibilities is indeed very wide. The basic functions of IP cameras today include the following:

  • control from a smartphone (setup, online viewing, etc.);
  • motion detection (with notification);
  • auto transition to night capture mode (thanks to the light sensor);
  • sound recording (microphone).
Most modern cameras can detect motion and notify the user through an application.

The scope of usefulness of individual models is extended by features such as:

  • speaker and feedback support (the camera can be used, for example, as a video nanny and communicate with the child by voice remotely);
  • active protection with sound and/or light alarms when motion is detected;
  • sound detection (activation and sending of notifications when detecting knocks on the door, breaking glass, etc.);
  • area of interest setting — provides setting the areas (separate parts of the frame), where additional analytical work will be performed (for example, motion detection);
  • various video analytics, including those based on artificial intelligence (AI) technologies. This includes people counting, person and vehicle detection, license plate recognition and/or face recognition, baby crying detection, etc. The range of these AI options will expand in the near future.

With advancements in video analytics capabilities of network cameras, additional selection criteria come into play. One such factor is the DORI distance, representing Detect, Observe, Recognize, and Identify. This range is closely tied to sensor resolution and lens focal length. A higher megapixel count in a camera corresponds to a greater DORI distance for detecting movements, monitoring people, and recognizing faces. The focal length of the lens also influences DORI, with larger values indicating more effective recognition and identification, emphasizing the importance of high resolution and longer focal lengths for optimal performance, even if specific values are not provided by the manufacturer.

Surveillance cameras with active protection

Video cloud storage

For network cameras, it is not necessary to buy DVRs with built-in hard drives or solid-state drives for video cloud storage. In most cases, models have a memory card slot (with support for various storage media up to 512 GB), and important files can be saved to a smartphone in a few clicks in the mobile application.

In addition, many manufacturers offer branded cloud storage with a free trial period (from 30 days to several months) and a subsequent paid subscription for use. This option is more convenient because it does not require additional settings. Sometimes there are not even restrictions on gigabytes: often tariff plans are tied only to the number of connected cameras. That is, in this case, the model can work literally non-stop and save all the videos.

In addition to branded services, universal clouds such as Google Drive can also be used to store video recordings. Here, as on a memory card, the amount of data is still limited, plus usually additional initial setup is required to work with such storages.

Despite their compact size, most cameras have a memory card slot.

Recall that there is a direct correlation between video resolution and the size of video files, so sometimes it is reasonable to reduce the detail or frame rate of video clips when the GB limit applies. In addition, it is very appropriate to trigger by motion sensor or even only when a person is detected (cases when a bird or an animal gets into the frame are filtered out).

What else to consider before buying a camera: additional options, brand, accessories

There are many other important factors in selecting a surveillance camera. For those who appreciate aesthetics, not the least role is played by the color of the body, because with its help it is possible to make the model as inconspicuous or fit it well into the interior (exterior), so that it literally was not out of sight in the design.

It is also worth considering the availability of cameras on sale that operate in 3G / 4G networks. They are in demand in areas where landline Internet is not available. And among other small but useful options of individual models, it is worth highlighting the presence of additional interfaces: from a microphone connector to alarm outputs — for operating with other security devices, including floodlights.

Of course, camera manufacturers deserve special attention. Reputable market players that have been building their reputation since analogue era (but they are well represented in IP category) are Hikvision (and its subsidiary brand Ezviz) and Dahua brands. A decent range of network models is offered by Ubiquiti, Imou and Axis. From the group of relatively inexpensive, but functional devices today we can highlight the products of TP-LINK, Xiaomi, Reolink and Tenda.

It would be a good idea to familiarize yourself with the available set of accessories before purchasing a camera. In addition to the basic devices, leading manufacturers offer various mounting boxes and brackets, IR projectors and lenses, remotes, moulages and much more. These accessories provide a neat mounting without wires sticking out in different directions, increase the level of enclosure security, and expand the overall functionality of the model.

Accessories provide a neat, secure, and even beautiful camera mounting.

In conclusion, we want to note that the purchase of one or more cameras, taking into account the recommendations in this article for a beginner will be very responsible, but it is not too heavy task. But the creation of a serious system for a large video surveillance object should ideally be preceded by design with the participation of professionals.