The Blackmagic Design CINEURSAMUPROTEF is a professionally engineered lens mount adapter that enables the use of Canon EF-mount photographic and cine lenses on compatible Blackmagic URSA camera bodies. This precision-machined component serves as a critical interface, ensuring not only a secure physical connection but also maintaining the correct flange focal distance required for proper optical focus. It is designed to preserve full electronic communication between the camera and the lens, supporting critical features such as autofocus (where supported by the lens), iris control, and image stabilization. This electronic integration allows filmmakers to leverage the extensive ecosystem of Canon EF lenses while utilizing the cinematic image quality and workflow advantages of the URSA camera system.

Constructed from high-grade aluminum, the mount is both lightweight and durable, capable of withstanding the rigors of professional film set use. The design includes a secure locking mechanism to prevent accidental lens detachment, which is essential when working with heavy cinema lenses or in dynamic shooting situations. The package includes a robust, custom-fitted protective case, ensuring the mount can be safely stored and transported without risk of damage to its precise mating surfaces or electronic contacts. This attention to protection underscores its role as a valuable accessory in a cinematographer's kit, where equipment is frequently moved between locations.

Functionally, this mount adapter unlocks significant creative and practical flexibility for URSA camera owners. It allows access to a vast selection of lenses ranging from fast prime lenses for low-light and shallow depth-of-field work to versatile zoom lenses for documentary and event coverage. By supporting electronic control, cinematographers can make smooth iris pulls during a shot directly from the camera or a remote controller, integrating lens control seamlessly into their workflow. This dedicated EF mount solution provides a reliable, feature-complete bridge between two major product ecosystems, empowering creators to build their ideal optical toolkit around the URSA camera without compromise.