Viltrox NexusFocus F1 Review – Autofocus for PL Lenses Put to the Test

Accessory Review

by Marcel KlienMarch 19^th, 2026

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The Viltrox NexusFocus F1 promises to bring native Sony PDAF autofocus and AI subject recognition to manual PL-mount cinema lenses, and after extensive testing, we can say it delivers on much of that promise. The adapter itself is well-built and impressively ambitious, while the bundled FIZ motors, though functional, leave some room for refinement in future revisions.

When we first encountered the NexusFocus F1 prototype at IBC 2025, we were so impressed that we gave it a CineD Best-of-Show Award. The concept was compelling: instead of relying on external LiDAR sensors (like the DJI Focus Pro), Viltrox taps directly into the camera’s own phase-detection autofocus system and translates that data into FIZ motor commands via USB-C. No parallax issues, no separate ranging hardware, and full access to Sony’s Eye AF, face detection, and touch-to-focus tracking. Since our initial coverage, the product launched on Kickstarter and quickly exceeded its funding goal, and now you can buy the final unit also from the Viltrox website. Now that we have had a final production unit in hand for an extended period, it is time to share our real-world impressions.

What you get in the box

Viltrox is clearly taking the hardware seriously with the NexusFocus F1. The adapter ring itself, which bridges PL-mount lenses to the Sony E-mount, is constructed from aluminum alloy and stainless steel, giving it a reassuringly professional feel. The kit ships in a dedicated hard-shell carrying case and includes the adapter ring with its integrated backlit status display, a Power Box module for regulating external power and managing motor voltage, your choice of two or three FIZ motors (depending on the kit selected), two extra gears for the motors, a complete cable set (three USB-C data/power cables for daisy-chaining plus one D-Tap to USB-C power cable), front and rear adapter caps, hex wrenches, a Torx screwdriver, and a focus test chart for calibration.

It is a comprehensive package that covers most rigging scenarios out of the box. The inclusion of the D-Tap cable is a welcome touch for professionals already running V-Mount or Gold Mount battery systems on set.

Camera compatibility

The NexusFocus F1 is designed exclusively for Sony cameras, which is worth noting upfront for anyone hoping to use it with other ecosystems. Compatible bodies include the Cinema Line cameras (FX3, FX6, FX30, and FX2), plus a range of Alpha series E-mount bodies such as the a6700, recent a7 series models with high-speed PDAF and AI processing, the a9 III, and the a6100/a6400. Since the system relies entirely on the camera’s phase-detection AF sensor and AI subject recognition, newer Sony bodies with more advanced AF engines will naturally deliver better results.

Setting it up on set

Getting the NexusFocus F1 rigged and ready is not particularly complex, but it does require some dedicated prep time before you start rolling. First, you mount the adapter onto the Sony E-mount body and then seat your PL lens into the adapter. Next, you rig the FIZ motors onto standard 15mm rods and align the motor gears with the lens rings. Cabling runs from your D-Tap battery source via USB-C to the first motor, and from there you daisy-chain additional motors using USB-C to USB-C cables, with the final motor connecting to the lens input port on the adapter.

One point of confusion for first-time users involves the Power Box. After speaking with a Viltrox engineer, we can clarify: the Power Box is not mandatory for every setup. If you are powering the system from a V-Mount battery or any reliable battery pack that outputs consistent power, you can skip the Power Box entirely. It becomes useful specifically when running from a gimbal or another power source that cannot deliver the constant voltage the adapter requires. This is not made immediately obvious in the documentation, so keep it in mind when planning your rig.

The NexusFocus app

The Viltrox NexusFocus app (currently iOS only) serves as the brain of the calibration and setup process. It handles smart calibration with stored lens profiles, firmware updates for both the adapter and motors via Bluetooth, and wireless remote control over focus, iris, and zoom. Manual calibration without a pre-loaded profile can take roughly 10 to 15 minutes per lens, so building a lens library ahead of a shoot day is advisable.

The good news is that the adapter and motors connect to the app instantly without any issues, and once your lenses are calibrated, you do not need the app actively running during a shoot. The less good news: the app still has bugs. One particularly frustrating issue affects users with European-region iOS devices. If your device is set to a European locale, manual lens calibration simply will not work. The workaround is switching the device to a US region setting, but it took us roughly two weeks of troubleshooting before identifying this specific issue.

Since our testing period, Viltrox has informed us that a new app update is rolling out this week, featuring a reworked lens library. Rather than relying solely on user-created calibration profiles, the update introduces an official Viltrox lens library that the company plans to expand with regular updates. At launch, the library is said to include profiles for the Blazar Mantis, DZOFILM Vespid Prime 2, NiSi Athena and Aureus, Canon FD Rehouse, and Viltrox’s own EPIC series. If this works as described, it would significantly reduce the time spent on manual calibration and address one of our biggest practical complaints during testing. We have not yet had the chance to verify the update ourselves, so we cannot confirm how well these pre-loaded profiles perform in practice; we will update this review once we have tested it.

For context, the Tilta Nucleus Auto Focus Adapter and the recently teased PDMOVIE SMART FUSION are both entering this same space, so how smoothly the software experience evolves will be a real differentiator going forward.

FIZ motors: room to grow

As someone who has worked with nearly every modern FIZ motor unit on the market, it is clear that the NexusFocus F1 motors represent Viltrox’s first foray into this territory, and for a first attempt, they get the fundamentals right. That said, there are a couple of areas worth flagging for potential buyers.

The first is physical size. The brushless motors are on the larger side, which can make mounting two units on smaller prime lenses a tight fit. The gear placement in the center of the motor (rather than offset to one side) adds to the challenge in compact configurations. Mounting one motor on the left side and one on the right would be a natural workaround, but the included USB-C cables are a bit too short for that approach.

The second consideration is noise. The FIZ motors run louder than some competing units, which is something to keep in mind for sound-sensitive shooting environments like close-range dialogue or interview work.

Who is this for?

The typical first AC on a large-scale production probably will not reach for an autofocus adapter like this. But the reality of modern production is that many jobs require only a single camera assistant, and budgets are tightening across the industry. Multi-camera interview setups, for instance, often benefit from having B, C, or D cameras running autofocus independently while the operator or AC concentrates on the A camera.

Hiring additional focus pullers for lower-budget projects is expensive, and those smaller productions are becoming increasingly common. Having secondary cameras equipped with the same lens family but running autofocus through the NexusFocus F1 can meaningfully improve the overall quality of the finished product. Solo operators and small crews should pay close attention to what Viltrox is building here.

Autofocus performance in practice

Once everything was properly set up and calibrated, the NexusFocus F1 performed well in our tests with minimal focusing issues. It is worth mentioning that we tested multiple pre-production and production firmware versions during our review period, and the final production firmware resolved the focusing inconsistencies we encountered in earlier builds.

Keep in mind that the NexusFocus F1 fundamentally relies on the camera’s PDAF sensor for all autofocus data, which means the system inherits the strengths and limitations of the camera body itself. Low-light performance, for example, can still be challenging, but that is a PDAF limitation rather than an adapter shortcoming. One practical tip: be mindful of where your PDAF sensor coverage sits on the camera body. The adapter cannot work properly if there is a loose cable or any physical obstruction in front of the sensor area.

Pricing and availability

The NexusFocus F1 initially launched via a Kickstarter crowdfunding campaign that ran from January 15 to February 13, with early-bird pricing starting at $699 for the dual-motor kit. Now that the campaign has concluded, the NexusFocus F1 is available to purchase directly through the Viltrox Store. Viltrox offers two configurations: a Single Motor Package at $599 and a Dual Motor Package, though the latter was listed as out of stock at the time of writing, but it can also be ordered at B&H (link below).

For comparison, the Tilta Nucleus Auto Focus Adapter starts at $269 for the adapter base kit (though it requires existing Nucleus motors), and the PDMOVIE SMART FUSION adapter is priced at $199 retail (requiring its own LIVE AIR 4 SMART motor ecosystem).

Conclusion

The Viltrox NexusFocus F1 is very much a product of two halves. The adapter itself is a brilliant, compact, and well-built tool that fulfills an ambitious promise: bringing native Sony PDAF autofocus to manual PL cinema lenses without LiDAR or parallax compromises. The potential here is enormous for solo operators, small crews, and anyone looking to breathe modern autofocus life into vintage glass.

The FIZ motors, while functional, are the area with the most room for refinement. Their physical size can create rigging challenges with smaller lenses, the included cables could be longer for more flexible mounting configurations, and the noise level is worth considering for sound-sensitive environments. For a first-generation product, Viltrox has built something genuinely impressive, and the new official lens library rolling out this week (which we still need to verify) suggests the company is actively listening and iterating. A future motor revision could elevate the entire system to match the ambition of the adapter itself.

Have you picked up the Viltrox NexusFocus F1 already, and if so, what has your experience been like? Or are you waiting for the competition from Tilta or PDMOVIE before committing? Let us know in the comments below!