Tamron 150-500mm Firmware Update Stabilizes its AF and Adds a9 III Compatibility

Dec 04, 2025

Kate Garibaldi

A woman with long brown hair holds a professional camera with a large telephoto lens outdoors, surrounded by green, blurred nature in the background.

Tamron has released a new firmware update for its 150-500mm f/5-6.7 Di III VC VXD (Model A057) telephoto zoom lens, bringing improved autofocus performance and full compatibility with Sony’s highest-speed cameras, including the a9 III and its 120fps continuous shooting mode, albeit with some unsurprising limitations.

Improved Autofocus Behavior

One of the primary Version 4.00 enhancements is better AF performance during zooming, a key feature when choosing a 150-500mm lens over a static prime. Telephoto zoom lenses often struggle to maintain precise focus as focal lengths shift, especially in AF-C mode, where slight variations can lead to missed moments. With this update, Tamron says that both videographers and still photographers should experience smoother, more consistent focus transitions when tracking subjects. The AF assist function has also been refined, improving how the lens responds in situations with low contrast or rapidly changing subject movement.

A table listing a Sony 150-500mm F/5-6.7 lens with firmware update Ver. 4 (Dec. 4, 2025); updates include better AF during zoom, 120 fps support, and improved AF assist function.

Unlocking 120 FPS With the a9 III

The most significant change is the lens’s new ability to support the a9 III’s ultra-high speed continuous shooting at approximately 120 frames per second when the camera is set to AF-S, DMF, or MF. Before this firmware release, the lens could not keep up with the a9 III’s burst shooting capabilities, limiting photographers who wanted to pair the body’s extreme speed with Tamron’s long-range zoom.

It’s important to note that while Firmware Ver. 4 unlocks continuous shooting at approximately 120 frames per second on the Sony a9 III, this ultra high speed mode is only available when the camera is set to AF-S, DMF, or MF. Continuous autofocus (AF-C) cannot be used at this frame rate, meaning photographers relying on subject tracking in AF-C will not benefit from the 120 fps burst. This limitation is critical for sports, wildlife, and action photographers who often depend on AF-C to maintain sharp focus on moving subjects. While the firmware update significantly expands high-speed shooting capabilities, users must carefully consider focus mode choices to ensure they capture the moments they need.

This is the same limitation on other Tamron lenses that have been updated to better work alongside the a9 III, like the 70-180mm f/2.8 G2 lens updated last year.

“As has been the case with other non-Sony lenses that have been updated to work at 120 frames per second, the 70-180mm f/2.8 G2 can only do so in specific focus modes, including AF-S, DMF, and manual focus, not with continuous autofocus. This is a significant limitation for some use cases, such as when photographing sports and action, but it could still work well in other scenarios,” PetaPixel wrote in late 2024.