CTV standard fixed lenses, also known as monofocal or prime lenses, are a popular choice for surveillance cameras. This is due to their budget-friendly cost, reliable performance, and optically stable design. Once installed, there is no way to change the focal length or zoom in on these lenses. Therefore, they are ideal for covering designated zones without the need for moving mechanical parts.
The focal length of a CTV standard fixed lens determines the width or narrowness of the camera’s viewing profile. Surveillance cameras typically have three focal lengths: 2.8 mm, 4 mm or 6 mm, and 12 mm or 16 mm+. Each of these lenses offers a different field of view (FOV). Consequently, each is suitable for different surveillance purposes.
The 2.8 mm lens, also known as the wide-angle lens, has an FOV of approximately 110°. Large estates, whole backyards, open interior lobbies, or corner-to-corner office spaces are the ideal locations for it. Its wider view allows for more coverage. Thus, it is an ideal option for monitoring large areas with fewer cameras.
The 4 mm or 6 mm lens, also known as the standard lens, has an FOV of approximately 75° to 50°. It strikes a balance between an overview and a clearer focus on distant targets. Because of this, it is perfect for tracking specific entry doors or longer room spaces where a more detailed view is needed.
For monitoring specific subjects or targets, the 12 mm or 16 mm+ lens, also known as the telephoto lens, is the best option. With an FOV of 30° or less, this lens narrows the view down to a precise subject. As a result, it is ideal for monitoring storefront cash registers, gates and identifying distant targets.
CTV standard fixed lenses typically have an S-Mount threaded design, which is most commonly used on small board cameras, mini-domes, and standard compact IP modules. However, larger professional box cameras may feature a C-mount. This uses a longer 17.5 mm lens-to-sensor flange distance for better image quality. The newer CS mount design uses a shorter 12.5 mm lens-to-sensor flange distance. Thus, it is more compact and easier to use than the older C-mount setups.
Overall, CTV standard fixed lenses offer a reliable and cost-effective solution for surveillance purposes. Their fixed focal length allows for a stable and consistent view. Moreover, the different FOV cater to different surveillance needs. With their various mounting options and versatile applications, these lenses are a popular choice for businesses and individuals. Many people look for a trustworthy and dependable surveillance solution.
