Focal length is a crucial parameter in the world of CCTV cameras, determining the field of view and magnification of the captured images. It directly influences the camera's ability to capture details at different distances. The focal length refers to the gap between the lens and the image sensor when the camera’s subject is in focus. This determines how far a camera can see and is often stated in millimetres. 

    For those seeking budget-friendly options in CCTV camera systems, there are certain focal length types that can offer cost-effective solutions without compromising on surveillance quality:

    Fixed Focal Length Lenses: These lenses have a single, non-adjustable focal length. They are typically more affordable and ideal for applications where the camera's position and focus point are constant.

    Varifocal Lenses: These lenses allow manual adjustment of the focal length, providing flexibility to modify the field of view as needed. While slightly pricier than fixed focal length lenses, they offer versatility without breaking the bank.

    Wide-Angle Lenses: Cameras equipped with wide-angle lenses come with shorter focal lengths, enabling them to cover broader areas. These lenses are excellent for monitoring wide spaces such as entrances, hallways, and small rooms, making them budget-friendly choices for comprehensive coverage.

    Fixed Zoom Lenses: These lenses offer a fixed zoom level and can capture detailed images at a specific distance. They are cost-effective options for scenarios where a specific focal length meets surveillance requirements without the need for constant adjustments.

    Megapixel and HD Lenses: Investing in a budget-friendly camera system that supports higher resolution lenses can provide better image quality even with shorter focal lengths. This can enhance the ability to capture clear details over a wider area.