Fujinon XA20sx8.5BERM ENG Lens with 20x zoom and 2x extender

The Fujinon XA20sx8.5BERM is a highly popular, cost-effective 2/3" B4-mount High Definition (HD) ENG lens designed for run-and-gun news gathering, field production, and studio environments.

As part of Fujinon’s eXceed Series, it balances pro-tier focal length ranges with budget-friendly optics. The crucial element of this specific part number is the "E" in BERM—which means it features a built-in mechanical 2x extender, a component entirely missing from its slightly cheaper sibling, the XA20sx8.5BRM.

Understanding the Focal Mechanics

The standard optical cell delivers a 20x zoom ratio ranging from a moderately wide 8.5mm out to a telephoto 170mm.

When a multi-camera shoot requires a tighter vantage point (such as tracking an event from the back of an auditorium or stadium press box), the operator flips a physical toggle wheel at the base of the lens mount. This drops a secondary optical glass cell into the internal light path:

• Standard Coverage (1x): 8.5mm to 170mm — Excellent for general room framing and standard field interviewing.

• Extender Engaged (2x): 17mm to 340mm — Shifts the camera layout deep into super-telephoto territory to pull across long distances.

⚠️ The Extender Light-Loss Tax: Engaging the mechanical 2x extender naturally spreads the light over twice the surface area. This results in an automatic 2-stop exposure loss (e.g., if you are running wide open at f1.8, dropping the 2x element down instantly reduces your maximum light gathering limit to $f/3.5$).

Technical Specifications Matrix

Core Ergonomic & Drive Tech

• eXceed Servo Grip: The right-hand control module is geometrically balanced to reduce wrist fatigue. It houses the primary variable servo rock, allow everything from a lightning-fast snap zoom across the entire 20x stack down to an ultra-low-frequency fluid crawl.

• Innerfocus Technology: Traditional lenses shift their front element during focusing, which alters weight balance and causes significant focus breathing (the image appears to change frame size as you pull focus). The XA20sx utilizes an internal focusing group, ensuring the physical length of the lens remains entirely static.

• QuickZoom Focus Check: A dedicated button on the side of the servo grip triggers a rapid override that flies the lens to the maximum 170mm telephoto limit in just 0.7 seconds. This allows camera assistants to instantly verify eyeball focus on a subject, and releasing the button snaps the lens back to their original framing.

Modern 4K Camera Usage Warning

💡 The Broadcast Sensor Fit: While the B4 mount allows this lens to physically click onto modern 4K workhorse cameras (like the Blackmagic URSA Broadcast G2 or Sony HDC series), keep in mind that the XA series features HD-resolved glass elements.

Because 4K image chips have a much denser pixel layout than older 1080i sensors, squeezing high-resolution 4K feeds through an HD lens block can sometimes exhibit noticeable color fringing (chromatic aberration) or slight softness along the extreme outer edges of high-contrast shots. For native 4K mastering environments, production houses generally favor Fujinon's LA or UA premium series lines.