Viltrox Fixes Sony A7 V Compatibility Issues With New Firmware Updates

Sony raised more than a few eyebrows when it launched the A7 V, especially among photographers and videographers who rely on third-party lenses. Shortly after the camera hit users’ hands, reports began surfacing that some non-Sony glass wasn’t behaving as expected on the new body.

Viltrox, one of the most widely used third-party lens manufacturers for Sony E-mount, acknowledged the issue last week and promised a fix. That update has now arrived, with new firmware rolling out for several lenses across its LAB, Pro, and Air series to restore full compatibility with the Sony A7 V.

Lenses Included in the First Firmware Wave

The initial batch of updates covers a broad selection of Viltrox’s most popular E-mount autofocus lenses. The following models now support the Sony A7 V after updating to the listed firmware versions:

• AF 135mm F/1.8 LAB FE (V1.28)
• AF 15mm F/1.7 Air E (V1.04)
• AF 35mm F/1.2 LAB FE (V1.09)
• AF 85mm F/1.4 Pro FE (v1.09)
• AF 35mm F/1.7 Air E (V1.05)
• AF 75mm F/1.2 Pro E (V1.08)
• AF 27mm F/1.2 Pro E (V1.20)
• AF 20mm F/2.8 Air FE (V1.13)
• AF 50mm F/1.8 FE (V1.08)

In addition, Viltrox released updates for a few other lenses aimed at improving autofocus stability and resolving known issues. The AF 24mm F/1.8 FE has been updated to version 1.07, the AF 28mm F/1.8 FE to version 1.08, and the AF 25mm F/1.7 Air E to version 1.05. These lenses are now also fully compatible with the A7 V.

Viltrox says more firmware updates for additional E-mount lenses are on the way in the coming days. The firmware update can be downloaded from the Viltrox Support Page. 

#Viltrox Latest Firmware Update.

⚠️More lenses will be added for compatibility with the Sony A7M5. Please stay tuned!
🔗 PC client file download at https://t.co/qNE8pWFDol
📪Viltrox Product Bug Feedback Channel [email protected] pic.twitter.com/fIMt8j5WlZ

— VILTROX (@ViltroxOfficial) December 22, 2025

Backlash Over Third-Party Lens Compatibility

The issue gained wider attention after YouTube creator Kai Wong published a video detailing autofocus problems with multiple third-party lenses on the A7 V, particularly those from Chinese manufacturers. That sparked speculation online, with some users accusing Sony of intentionally limiting third-party lens performance.

“All autofocusing Chinese lenses I tried had some kind of problem,” Wong said. “Maybe it’s an early firmware problem, but definitely something to keep an eye on. I’m not judging — it’s entirely up to the brands to decide who they open up their system to — but if it’s intentional, some warning wouldn’t go amiss.”

While the frustration was understandable, Viltrox pushed back against claims of deliberate interference from Sony. According to Frank Fang, Viltrox’s US Marketing Director, nothing suggests Sony intentionally broke third-party lens compatibility.

“Nothing we’ve seen so far suggests any intentional behavior on the camera side,” Fang said. “This appears to be part of the normal post-release optimization that often occurs as new camera systems are introduced.”

Fang added that firmware tuning after the release of new camera bodies is common across the industry, as lens makers validate performance in real-world shooting conditions.

For Sony shooters relying on Viltrox glass, this firmware update should come as welcome news — and a reminder that early compatibility hiccups don’t always mean foul play.

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