Fuji Viltrox Pro lens AF-C tracking and vignetting vs. Fujifilm lenses?

[TumblingTiger]

For those who have used the Viltrox Pro 27mm or 75mm lens on a Fujifilm X-T5 (or T3 or T4), have you noticed the AF-C tracking with people/faces moving toward/away from the camera to be a bit unreliable? I find the lateral tracking to be fine, but finding & locking on a face moving toward or away from the camera is hit or miss. Additionally, I sometimes find image rendering, especially in low light situations to be inconsistent with more vignetting than I see on Fuji XF lenses.

I love the IQ, sharpness, and AF-S performance of these Viltrox Pro lenses. The sharpness in details seems to consistently exceed what I can achieve with comparable Fuji XF lenses. However, I've noticed some focusing issues, especially when I compare the Viltrox Pro 27 1.2 to something like the Fuji XF33 1.4 WR with stellar IQ and AF-C tracking.

Curious if others have noticed either of thse issues with the Viltrox Pro lenses? Or if this comes down to user error on my part (definitely a possibility!)

 

[mnhoj]

I had pretty good results with the 75. As good or better than the 56WR I'd say. But did see inconsistencies with both lenses in that situation.
I had better results with the 33WR but chalked it up to DOF differences. I didn't get a chance to try the 27.
I wouldn't expect the 27 to keep up with the 33WR (I felt like this was one of Fuji's best when it came to AF), but I'd keep trying and build more data.
Maybe update firmware for the 27 if you haven't.

 

[Out to Lunch]

I'm not too sure how much of that would be attributable to the camera body or the lens, keeping in mind that Fujis are not great in the AF-C department. Cheers, OtL