Logic can only lead me to believe that the problem is in the 16-35mm.....
What is 'Logical' to one person may have a different meaning to another.
I searched on Google for autofocus problems with this lens.
Besides several messages found of your own copies having trouble.
I only found a message, that under dark conditions this lens do have more AF problems.
Well, that is nothing new. All lenses with less fast starting aperture values, shall met AF problems sooner under dark conditions.
Specially in comparison to the older S1 / S1R camera models, known for their less fast / reliable AF, than e.g. te more new S5 II model.
But that is more a camera issue than a lens issue.
But NO messages found as for problems as mentioned by yourself.
Even the opposite fast and reliable AF - (by a more old review).
The Panasonic 16-35mm f4 is a lens that is easy to love. But at the current price and with this autofocus, we're finding it a tough decision.
www.thephoblographer.com
As of May 2021, the Leica SL2s received a big firmware update. For stills shooters, that update brought a lot of autofocus upgrades.
The Panasonic 16-35mm f4 now autofocuses faster on the Leica camera than it can on Panasonic’s own cameras.
What’s more, the autofocus is accurate. Tracking autofocus and continuous autofocus work well for journalistic situations.
"By logic" if there is a main AF problem by this lens "by design", I should find many, many more messages of users having comparable problems..
And at least a lens firmware update for correction that should be related to those issues "if there was a general complain" of AF issues.
But there isn't either. The only
firmware update (v1.1) = "Improved optical correction control" (whatever that may entail).
So "by logic" I think in one way or another it could be that you are using the wrong AF focus technique itself ?
(As I explained earlier in my previous post, how to deal with it).
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