If you are concerned about Sony a7RII low-light AF speed with native vs non native lenses. This will be very helpful for you.
The test results: Both lenses perform well, but the native Sony Lens is clearly faster. A tripod was used to keep the subject identical.
Check out the video below:
Sony a7RII Low Light Focus Tests: Canon EF 40mm f/2.8 STM Lens vs Sony Sonnar T* FE 35mm f/2.8 ZA Lens
In Unite States: