Security cameras come in a range of shapes, sizes, and functionalities that allow them to perform in different situations and settings. Surveillance cameras can be divided into a range of categories including Movement, Size & Shape, Functions, and Housing. Keep in mind that security cameras can be organized into multiple categories and can include various features.
Movement:- Fixed security cameras typically stay in the position they are mounted for the lifetime of their deployment. Since the only way to move them is to either reposition or remount the device, fixed cameras are used to make sure that the subject in frame is perpetually on surveillance.
“Fixed” can also refer to the type of lens on various types of security cameras. A fixed lens doesn’t let you adjust the focal length, angle of view, or level of zoom. Nearly all fixed lens cameras have a wide-angle lens. When it comes to security camera lenses, the opposite of fixed is varifocal.
- Applications – Fixed area of focus for continuous recording of a single area.
- Advantages – These low-cost, uncomplicated security cameras are ideal for most consumers as you can simply mount the camera and point it at a target area, with no adjustments to be made with lenses or motors.
- Disadvantages – Since these security cameras can only be moved manually, footage just outside of frame will not be able to be captured. Additionally, the only way to enlarge video footage is to zoom digitally, which can cause pixelation at lower megapixel ratings.
A manual varifocal lens has an adjustable focal length. By adjusting the focal length, you can manually select the horizontal field of view of the security camera, allowing you to narrow the field of view to gain more detail of any monitored area. These varifocal lenses can also be motorized, which we will cover next.
- Applications – Allows you to manually focus on an area from a distance when more detail is required. For example, capturing license plates and other details at an entrance when the security camera is mounted a distance away.
- Advantages – These adjustable lenses allow you to manually select the level of detail of video recording you desire, only limited by the camera’s megapixel rating and lens.
- Disadvantages – With a manual varifocal lens, you’ll have to physically take the lens off in order to manually adjust the lens to your desired focal length.
A motorized varifocal lens is sometimes referred to as a zoom lens. These motorized lenses allow you to adjust the focal length of the lens from a user interface on your video management software via your computer or smartphone. Zoom lens adjustments are typically expressed as an optical zoom ratio. For example, 30x optical zoom refers to the difference between the smallest and largest focal lengths or 4.3 mm to 129 mm.
- Applications – With a motorized lens, you’ll be able to manually, or automatically based on motion, adjust the focal length at any time. This allows you to focus on finer details of objects or people in real-time via a mobile or desktop application.
- Advantages – Zoom lenses typically have a much larger range of adjustment than varifocal lenses. A zoom or motorized varifocal lens is the next best thing to a PTZ camera, but is typically less expensive.
- Disadvantages – More expensive than a manual varifocal lens, but zoom lenses will still be hampered by a limited field of view since the security camera itself doesn’t move — just the lens.
PTZ or Pan-Tilt-Zoom security cameras are able to adjust the field of view manually via a remote operator or using software applications to track movement or people. These top-tier cameras have the ability to pan, tilt, zoom and track specific subjects in real-time.
- Applications – PTZ cameras can cover a huge area but are typically used in conjunction with fixed security cameras. Most street cameras in large public spaces today are Pan-Tilt-Zoom cameras.
- Advantages – Besides the ability to cover 360-degrees of any area, there are plenty of advantages to owning a PTZ camera. These motorized devices can respond to or track intruders by whoever has access to the software. They can also be configured to do manual patterns, or tours, where they can view predefined areas on “autopilot.” Their ability to cover large areas may allow you to reduce the number of cameras in a given area.
- Disadvantages – Although one of the main advantages is coverage, PTZs are some of the most expensive security cameras and can only see and record where they’re pointing at a given time. So if you need continuous 360-degree coverage, it’s best to couple a PTZ with a fixed security camera. On top of that, these systems involve more motors, software programming, and configuration — so there’s a lot more that can go wrong.
Virtual PTZ cameras combine some of the benefits of both fixed and PTZ cameras through software. Virtual PTZ security cameras include multiple fixed lenses which are typically positioned in order to achieve a 360-degree field of view. When the operator views the live or recorded footage, each of the video streams is tethered together in order to provide one seamless panoramic image. Virtual PTZ users can use their recording software to digitally pan, tilt, or zoom in on specific subjects just like a standard PTZ. However, virtual PTZ cameras continuously record all angles of video that the lenses are capturing, even if you’re manually zooming in on a specific target.