Sony E-mount system is specifically known for its open mount design and the wide range of lenses available for photographers, and recently, Sony has announced the Sony A7 V camera with a 33-megapixel stacked CMOS sensor, blackout-free continuous shooting at 30 frames per second. Not only that, the camera also features an advanced and newly developed image processor with an integrated AI chip, loaded with the same autofocus algorithms as we have seen in the Alpha A1 series flagship camera. All that has been done to boost the autofocus performance of the Sony Alpha A7 series.
However, a recent video posted by Kai has sparked a new controversy related to Chinese-made E-mount lenses from brands like Viltrox and Yongnuo. When using lenses from these Chinese brands, the Sony A7 V camera completely stopped focusing, rendering the lenses seemingly useless.
Any silly thought that it is affecting only one lens, but after testing and trying several lenses by other reviewers also, it has been found that the problem exists with almost all Chinese E-mount lenses made for Sony Alpha A7 series cameras, possibly a strategic move by Sony to temporarily cut down the pipeline of unlicensed Chinese lensmakers for a while. But why Sony has done so? It’s quite obvious — they would like to generate a bit more revenue, just like Canon, by asking licensing fees from third-party lensmakers, but that’s our thought process.
Full story on Sony A7V third-party lens compatibility, Chinese E-mount lenses issues, and what it means for your next gear upgrade.
The Breaking Issue: What’s Going Wrong with Chinese E-Mount Lenses on the Sony α7V?
The first person to raise this issue is Kai W., who has well-documented the problem in his video, which you can also see above. He was using a Chinese third-party lens made by Viltrox — the 85mm f/1.8 — on the Sony A7 V camera, which in turn resulted in zero autofocus response, aperture glitches, and the camera completely froze, becoming non-functional and unable to shoot a single image or video clip.
At the end, what they found was that by attaching third-party Chinese lenses on the Sony A7 V camera, the camera became completely disabled for capturing images or videos.
When I asked Sony officials about this issue, they replied:
“We don’t guarantee compatibility with third-party products.”
The one thing that came in support of Sony is the next generation of the Sony image processor, which is the BIONZ XR Mark II. It actually requires precise lens communication protocols that budget Chinese optics may not yet support. So, the cameras that are coming in the near future and integrated with the BIONZ XR Mark II image processor may also not support these Chinese E-mount lenses.
Users Opnion on X
On X (formerly Twitter), the backlash is real. One user lamented, “Sony reverse-engineering lenses means this was inevitable—α7V owners with Viltrox kits are in limbo.” Another praised Yongnuo’s optical quality but warned, “Snagged an 85mm for pennies in Shenzhen, but if it bricks on A7V? Back to square one.” Views on these posts have skyrocketed past 90K, signalling widespread concern among hybrid shooters eyeing affordable glass.
A Quick Primer: Sony E-Mount’s Open Legacy and the Third-Party Boom
Sony’s open-lens E-mount strategy actually took a serious turn back in 2018, where the company cemented their partnership with four trusted third-party lensmakers. The list includes Tamron, Sigma, Tokina, and Zeiss.
Sony granted them access to AF algorithms and firmware communication protocols, and added all four third-party lensmakers to their official collaborators list. Because of this, they do not need to reverse-engineer any Sony lens, and they already have all the algorithms required to create the best possible autofocus lenses for the E-mount system.
Partnered Powerhouses vs. Chinese Contenders: Who Wins on the Sony α7V?
No, after 2018, Tamron, Tokina, and Zeiss created a “fast lane” for compatibility with all future Sony cameras. Everything is going smoothly with all these four official partners, but a lot of other third-party lensmakers, specifically emerging from China, have entered the market like Viltrox, Yongnuo, and more…
They have done a lot of reverse-engineering work with all the possible Sony native lenses and other third-party lenses by accessing their firmware. But since the communication isn’t licensed or official, these lenses struggle the moment Sony updates its firmware or image processor architecture.
Now compare that with Chinese lenses — for example, the Viltrox 85mm f/1.8, which has been a bokeh monster on older Sony bodies. But on the Sony A7V? The AF starts hunting like we are back in 2015. Same story with Yongnuo and 7Artisans — optics are sharp, no doubt, but the electronics just can’t keep up.
And the reason is simple: these unofficial mounts don’t support full data communication. They miss out on the exact command sets required by the A7V’s new processing system for subject detection, real-time tracking, and burst stabilization.
| Lens Brand | Partnership Status | α7V AF Performance (Early Tests) | Price Range (85mm Equivalent) | Best For |
| Sigma | Official (2018+) | Full 30fps tracking, Eye AF lock | $800–$1,200 | Pros needing speed |
| Tamron | Official (2018+) | Seamless aperture control, no lag | $600–$900 | Versatile hybrids |
| Zeiss | Official (2018+) | Precise manual override fallback | $1,000+ | Cine/video purists |
| Viltrox | Unofficial (Reverse-Eng.) | AF failure, aperture glitches | $300–$500 | Budget stills (pre-update) |
| Yongnuo | Unofficial (Reverse-Eng.) | Basic MF only, burst drops | $200–$400 | Entry-level experiments |
Data compiled from DXOMARK, SAR, and X user reports. Bottom line: If you’re all-in on the α7V, stick to partnered glass for peace of mind.
Don’t panic-sell your kit yet.
Viltrox is in its high-performance form right now, and we do believe that at least this brand will quickly figure out a solution for these issues – and later on, other Chinese lensmakers will follow the same path. So, after seeing all this news, don’t take any impulsive decision yet.
But yes, if you are planning to buy the Sony A7 V camera and you also have a bag full of Chinese E-mount lenses that are not from brands like Sigma, Tamron, Zeiss, or Tokina, then you definitely need to think twice before making your purchase decision.
It’s best to wait a month or so until we get a clear and official picture of what’s actually going on with the new Sony A7 V camera and Chinese lenses.
We are keeping an eye on this issue, and we will update you as soon as any new information related to the Sony A7 V camera and Chinese lens compatibility arrives.
Stay tuned. Stay updated.