Has anyone had a Samyang/Rokinon lens that just quit autofocussing all of a sudden? I was using the Samyang 135/1.8 at an event and it went from autofucussing fine to not being able to focus at all while I was shooting with it in either video or stills. I don’t think it’s a firmware incompatibility or anything because the change happened mid-shoot rather than after I updated anything. If you’ve had that happen, did you find a fix?
I just had this happen with my SY50AFII over the weekend when mounted on the A1ii. (Don't laugh - I don't like shooting 50mm and purposely cheaped out on buying 50mm lenses).
Anyway, I was using a CPL in broad daylight and the lens and camera were hunting like crazy in AF-C mode on barely moving subjects. Although I have only had the A1ii for a couple of months, I've used it with a few of my Sony primes, and it focused quickly and confidently in substantially worse lighting situations.
Interestingly, I turned my CPL 1/4 turn and voilà! The Samyang locked and tracked focus in AF-C and pixel peeping photos taken at f/1.4, it nailed focus every single time.
Not sure if that was your issue or not. I have also tried to focus slowly moving subjects with the A9iii and this lens and it completely failed. I reshot the same situation with the ZA55 and same body and had no issues, so I suppose I would call the Samyang's AF capable "barely passable" at best. But again, I don't like shooting 50ish, so I knew the tradeoff up front on saving money.
