The Fujinon ACM-18 EX3 is a specialized, high-performance optical adapter designed to enable the use of premium 2/3-inch broadcast B4 mount lenses on professional cameras equipped with a 1/2-inch image sensor. This adapter addresses a critical need in the industry, allowing broadcasters, production companies, and camera operators to leverage their existing investment in high-quality, large-format B4 mount zoom lenses—such as Fujinon's own HAe and HPx series—with newer, more compact camera bodies that utilize smaller sensors. The adapter incorporates advanced optical elements that efficiently concentrate the larger image circle produced by the 2/3-inch lens onto the smaller 1/2-inch sensor. This process, known as "optical compression," preserves the lens's original angle of view, effective focal length, and, critically, its f-stop, ensuring no loss of light transmission and maintaining the lens's characteristic optical performance.

The design of the ACM-18 EX3 is engineered for precision and reliability. It maintains full electrical communication between the lens and the camera body, supporting essential functions such as auto-iris control, built-in optical image stabilization (OIS), and lens data transmission for metadata recording and camera setup. The adapter is constructed with a robust metal housing that ensures a secure, stable connection between the lens and camera, maintaining optical alignment and preventing any play or movement that could degrade image quality. Its optical path is designed to minimize aberrations, flare, and ghosting, delivering sharp, contrast-rich images that meet broadcast standards. The unit is also relatively compact and lightweight, adding minimal bulk to the camera rig, which is important for handheld or shoulder-mount operation.

This adapter is a vital tool for broadcast ENG (Electronic News Gathering) and EFP (Electronic Field Production) workflows where crews need to pair their familiar, fast, and durable broadcast zooms with modern, more affordable, or logistically advantageous 1/2-inch sensor cameras. By bridging the gap between different lens and sensor formats, the Fujinon ACM-18 EX3 extends the lifecycle and utility of expensive broadcast lenses, providing a cost-effective pathway to adopt new camera technology without sacrificing optical quality or operational familiarity. It represents a sophisticated optical solution that upholds the image integrity demanded by professional video production.