After you decide the type of camera you want to use and how many, it's necessary to check certain features in the product you will buy. For example,  before purchasing a camera, you have to make sure that it has a motion detection feature to never miss any activity on your property. Another important feature is night vision; it is very useful for dark areas or at night. In such cases, images or videos recorded will be clear and easy to understand.

1. Person or Face Motion activation 

Person detection or Face detection with motion activation allows the camera system to always be on for live viewing and automatically record what's important when it detects human movement.

2. Face Recognition 

People often ask for facial recognition. If a surveillance camera captures the image of someone, it will start recording. Face Motion activation cameras are a popular way to do this work by using a motion detection algorithm to detect and track the user's face.

Face Recognition is a more complex feature that uses frames with faces to initiate face recognition. This can be done in-camera in the more expensive cameras or in the cloud

This is achieved with the help of specialized software that can create a face model based on video with facial features and recognize people based on a database. 

With more sophisticated software it is possible to track how a face moves from area to area. Most systems are based on analyzing moving faces by measuring the movement between frames for a more 3-d image and processing is done using the OpenCV library, which translates into hashes. 

There are many levels of face recognition and applications from a white list of employees to open doors to a connection to a national police database or a store that tracks people that have stolen there before.

Deep learning or AI Facial Recognition  is becoming a reality for both in-camera and cloud analytics. It is a useful feature when you need to compare people against a database. For example, white list employees or contractors to the building but give alerts to guards to non recognized people.

Such a system allows you to easily search the videos using a person's name or even tag them so you can quickly access them later on and can save a lot of  time by eliminating the need to go need to go through hours of video footage and scroll through hundreds of different video files to find out whether this person was in front of your building on a specific day at a particular time. It's true that facial recognition technology is not perfect and may not work all the time correctly. However, it works well enough to be extremely useful.

3. Wireless Connectivity 

Wireless Connectivity is a feature many people consider to save on cabling. We recommend wireless cameras only for some areas in businesses, mainly for outdoor cameras pointing back to the building or that are connected to a central wireless Internet access point.

For most indoor commercial applications we recommend sticking to POE wired cameras. POE stands for Power over Ethernet and it has the advantage that your cameras will not need outlets for small local power adaptors that when visible look unsightly and could be unplugged easily to disable your surveillance. They are also unsafe in humid areas. 

POE mixes the ethernet and 48 Volt power on some pins in the same ethernet cable and makes for very clean installs with only one wire. 48V is also considered low voltage and in most states does not require a certified electrician. 

Wireless where convenient will provide basically the same quality as wired connectivity when set up well. It can transfer image and video files from your  Wifi Network. When connected directly within your network you get what is typically known as a WiFi Camera. To be able to access this from the outside will require a service provider. Most consumer product service providers for WifI Cameras do not have very sophisticated privacy and are not suitable for commercial deployments.

Some Wireless cameras are more advanced than others and can record internally.  They will save video internally on a memory card and even to the cloud. Some models will have night vision, and even larger batteries to run even without power. The best part of these cameras is that they are wireless, so you can move them around without long ethernet cables as long as there is a plug for the power adapter and or there is power in the battery.  This shows that these cameras are useful for shorter projects more than long-term deployments.

One thing to consider is that wireless cameras are sensitive to interference from things like microwaves and will be disrupted by any cheap WIFI jammer.  

4. Video Resolution 

Video Resolution is one of the most important and also often misunderstood aspects when deciding on a security camera. 

The number of pixels used to show an image is the camera's resolution. The greater the number, the more detail that can be captured. For example, a photograph taken by a camera with a resolution of 1 megapixel can display 2,048 rows and 1,024 columns of pixels. In contrast, a camera with 5 megapixels can capture 4,096 rows and 3,072 columns.

For example, a 4MP camera may have better resolution than a 2MP camera. However, the fact is that 2MP cameras have higher resolution than what the human eye can perceive. So the video quality difference between a 4MP and 2MP camera can be negligible if there is no need to zoom. 

On the other hand, when using wide-angle cameras zooming is important to get closer up and this is where a higher resolution like 4 or 5 MP makes sense.

When shopping for a security system, look for a camera with a minimum of 1080p and above, and be aware that most cameras are not constantly recording—you will need to initially tune what areas are supposed to trigger recording and initially always review footage manually and when there is an incident to make sure you get recordings of what you really want. Ideally, you will have more than one camera with different trigger times. 

Some advanced cameras have higher night vision than others. Typically the higher the resolution the worse the night viewing which is another reason not to chase 8 or 10 MP cameras and stay in the 2-5 MP range. 

Most of the robberies and theft occur at night so it makes sense to get IR illuminated and good night view sensors. Many new cameras have sensors and lenses that make them even see colors in very dark conditions. This will help identify the person.  

High Aperture lenses used in the cameras like F/2.0, or smaller numbers are good for that. The smaller the aperture number the more light the lens can gather versus other types of lenses. 

The second thing to look out for is the sensor kind.  Ideally, a CMOS Sensor with a feature called a "rolling shutter" can perform faster than other sensors by just reading one line at a time instead of reading all pixels at once. This helps a lot for movement detection or fast-paced events like sports photography; capturing moving objects is much easier and more precise with this sensor.

Last but not least advanced cameras have some kind of an auto exposure algorithm that ensures images appear brighter, sharper, and more saturated. It's also a feature that can make a big difference for anyone who likes to take photos of nightscapes or very dark objects.

5. Two-Way Audio 

Two-Way Audio is another important feature that is available in premium cameras or can be added to some cloud cameras with an external audio adaptor that virtually assigns the audio stream to a specific camera.  This enables listening and speaking directly to the camera in the two-way audio way. This is a great addition to any security system. To hear what is going on can help identify if there is a real threat and in many cases talking to or playing alarm siren sound can be used to scare or dissuade an intruder or robber.  So if there is a suspicious person or vehicle in front of your building, office or home, you can alert them that they were seen and tell them to leave before having to call the police.

Two way audio can also be used with packet services and to talk to employees on the factory floor as a way to communicate during emergencies, shutdown maintenance and many or other situations. 

Basically the audio capabilities allow you to speak and listen directly to the people near your cameras, which adds a potential productivity dimension and a layer of security to the value of your video platform. IPTECHVIEW for example, couples security audio from MOBOTIX cameras with VoIP and offers a phone system integration.  

6. Video Storage

When deploying cameras the next issue is always video storage. 

Suppose you are looking for a surveillance system with excellent video quality and long-term storage options. In that case. You need to ensure that the company you hire for video surveillance will provide you with an excellent video storage mechanism, to ensure that your recordings are safe and will survive even if there is a power failure or there are other problems with your system.

A security system with video storage should allow you to go back and watch the footage if you missed something while it was happening or if you want to review the footage after an incident has occurred. In addition, ideally your solution will let you view stored footage over the cloud on a mobile device like a smartphone or tablet so that you can check in on your camera feeds from anywhere in the world.

Video recording capabilities aren't just useful for catching criminals red-handed; In today's Hybrid world video surveillance in commercial spaces is beginning to be used for much more than just loss prevention and classic security. 

It is being used for training and education, insurance purposes, catching employees doing great things, catching contractors doing shoddy work, for doing QA, or to ensure procedures and workflows are being upheld. The last thing anyone wants is a lawsuit because someone got hurt due to neglect or other situations  that could have been prevented if noticed. 

7. Angle of View 

The Angle of View is the total viewing area that a camera sensor can cover. Therefore, it directly affects the scene's size that can be captured. This is an important factor when considering what kind of camera to buy since it defines what type of photos or videos you will be able to generate and view with your camera. 

The security camera's field-of-depth, defines a range of distance for a camera where objects are at their maximum sharpness. This can go from 1m (3') to infinite in fixed focus lenses or can be relatively narrow in tele lenses. When an object is in view of the camera but outside of its field of depth range objects are blurry and people may no longer be recognizable. 

For example, a wide-angle lens has a wide field of view, while a telephoto lens has a narrow field of view. 

In general it is better to have security cameras with a wider angle of view, because the probability of seeing an incident is higher.  The larger the camera's angle of view, the larger the area it covers, which will also save budget because you can use less cameras, but it is critical to use higher resolutions like 4-5MP on all wider angles because you will need to zoom in more when you do notice something to see details.  

8. Durability 

Durability is one of the most important things that we look for when selecting brands and deploying cameras. It is a universal rule that  items that last longer will provide you with a bigger value than buying a cheaper version. With today's cost of labor the installation time literally costs you more than the camera itself so always go with a quality product and even get an extended warranty to match the lease time you have left in your building.

A security camera should be designed for maximum durability. You do not want to worry about it failing in 1-2 years. There is absolutely no point in investing in a cheap camera that will go bad in 6 months to  2 years.

9. PTZ - Pan Tilt & Zoom Surveillance Cameras

A  Pan Tilt & Zoom Camera (also known as PTZ) allows a camera to rotate its sensor left, right, tilt up and down and zoom in and out. This allows for a single camera potentially having a very wide range of view and can enable very targeted and focused shots than if the camera were a stationary wide angle camera. PTZ is used in the security camera world mainly by a human operator trying to discern details or to see far away things. Its strength is the ability to zoom into details and auto focus at distant things. Its weakness is that it only sees what the human operator focuses on. In practice security guards can get distracted by an accomplice who gets the attention of the security guard on a PTZ camera and the camera system if it does not have wider angle cameras over seeing the same area will miss the real action. Only buy PTZ cameras if you will have live human operators

Multiple PTZ provide the ability to view a scene from multiple angles by pointing multiple cameras to the same spot. It can also be especially useful when looking to cover an area with many local obstacles within the to be protected area.

One of the most popular uses for PTZ is coverage of parking lots. Security cameras are often used outdoors, where it is difficult to adjust the position of a stationary camera as needed. By using PTZ, these cameras can be adjusted easily to follow movement or zoom in on important parts of an image. This also makes it less likely that criminals will notice that a camera is present and cause them to avoid committing crimes near it.

This technology can also be used in other ways, such as providing hands-free viewing from a distance or allowing viewing without disturbing people in an area by having the camera automatically focu on moving objects that way guards can inspect vehicles and people without having to go there.