A CS mount fisheye lens is a type of camera lens that is designed to capture a wide-angle view of the scene with a distortion effect that creates a circular or hemispherical image. The CS mount refers to the type of lens mount used by the camera, which is a screw-on type of mount commonly used in surveillance cameras and other types of security cameras. Fisheye lenses are typically used in photography and videography to capture unique and creative perspectives of the scene. They can be used to capture immersive 360-degree panoramas, architectural interiors, and other types of wide-angle shots. The CS mount fisheye lens is a popular choice for security and surveillance applications because of its wide field of view and distortion effect, which can provide a more comprehensive view of the scene. When selecting a CS mount fisheye lens, it is important to consider factors such as the lens focal length, aperture, and image quality. Some lenses may have a fixed aperture, while others may offer variable aperture settings. Additionally, some lenses may have built-in image stabilization technology to reduce camera shake and improve image quality.