The TV2713D-4MPIR CS-Mount 2.7-13mm Varifocal Lens from Hikvision is compatible with 4MP cameras that have a 1/2.7” sensor. This IR-corrected varifocal lens features a 2.7-13mm focal length, manual focus and zoom operation with locking screws, and a DC auto iris.

TV2713D-4MPIR is a DC Iris is a type of lens where the iris opening can be controlled by a DC motor. It uses a DC motor to open the iris and spring tension to force the iris to close. DC Iris was introduced by the security camera market with analog cameras many years ago and is one of the most popular auto iris technologies today. Due to its popularity and availability, digital cameras have adopted this technology.

TV2713D-4MPIR is a DC Iris lens consists of a DC motor used to move the aperture in one direction and a spring to return the aperture to its original location, typically closed. The lens relies on a reference signal, which it compares with a control signal supplied by the camera to determine whether the iris should open or close. If the control signal amplitude is higher, the lens is opened, and if the control signal is lower, the lens is closed. Because the camera can never perfectly match the analog reference, the iris does not rest and will continue to drift in either direction until the control signal is updated again. For this reason, continuous imaging is preferred when using DC auto iris lenses.