Some key professional skills in industrial lenses(4)

CCTV Lens: A lens designed for extensive surveillance coverage, typically used in closed-circuit television (CCTV) systems. It is suitable for wide-ranging observation but not ideal for applications requiring high precision. The optical system is set to infinity focus, where light from the objective lens does not converge and moves forward in parallel.

Zoom Lens: A lens with variable focal lengths that can easily adjust the magnification and field of view. This flexibility is useful for finding optimal shooting conditions, such as varying photography distances and focal lengths. Zoom lenses that maintain focus while changing focal lengths are called parfocal, while those that require refocusing are known as varifocal lenses.

Image Circle: The size of the optical system's image circle, which should match the diagonal size of the charge-coupled device (CCD). The image circle size corresponds to the CCD size and is critical for determining the lens's coverage and compatibility with different sensors.

Rear Teleconverter Lens: A lens that mounts in front of the CCD without altering the working distance, providing an expanded field of view. However, it can lead to decreased F-values, resolution, and contrast, and may slightly affect focusing accuracy.

Front Teleconverter Lens: A lens that mounts in front of the main lens, altering the working distance to expand the field of view without affecting brightness. It changes the working distance but keeps brightness constant while increasing the field of view.