At InterBEE 2019 in Japan, Fujinon was demonstrating their A 107x8.4 AF Outside Broadcast Lens with Auto Focus for the first time. This lens was originally announced prior to IBC in September and was only being shown under glass. Today we got to get some hands on time with the new lens and see how the auto focus system performed.
   

Fujinon claims this is the world’s first 4K box lens to feature autofocus. The lens is due to be released in February 2020 and will be in use for the 2020 Tokyo Olympic Games. This new lens is based on Fujinon’s 4K Premier UHD UA107x8.4 Box-Type 107x Zoom with OIS that is already in the market.

The auto focus can be used in continuous on one shot modes. You can move a box around on the screen via the focus controller to grab focus. The system worked reasonably well when in continuous auto focus mode, but it does struggle in low light or high contrast conditions.

The UA107x8.4 AF broadcast lens incorporates a newly developed phase-detection autofocus sensor, that Fujinon says achieves fast, tack sharp images with a response speed as quick as 0.5 seconds. It can also track a moving subject. The lens also features the company’s proprietary image stabilization mechanism and a 107x ultra-magnification zoom that covers focal lengths from 8.4mm to 900mm (1800mm with 2x).

Autofocus has traditionally been reserved for consumer and prosumer lenses. What is interesting to me, is that the UA107x8.4 AF’s phase-detection AF sensor and dedicated algorithm was derived from technology used in Fujifilm’s X Series and GFX digital cameras.

With ultra-high-definition 4K video creation now becoming a lot more mainstream, the demand for 4K content is picking up. For outside broadcast camera operators, this move towards 4K capture will make it harder to manually achieve fast, precise focusing. That is the primary reason Fujinon has made this lens.

The lens is well suited for covering live sports and entertainment. The UA107x8.4 AF uses aspherical and fluorite elements to effectively control various types of aberration, as well as Fujinon’s unique multi-layer coating (High Transmittance Electron Beam Coating) for good light transmittance.