AFS-S issue - Returning my XT5

Alessandro63 wrote:

There's an "issue", which is surely just a Fuji's choice, that's present in every model: AF in fuji cameras is achieved using the actual aperture, up to 7,1. Everyone can check/verify, it just takes some experimenting (looking inside the lens while focusing; just some... inventiveness required to do it right).

The outcome is that it sometimes misses a bit, just enough to find a slightly "muddy" look when pixel peeping. Probably, with the newer sensor it's more apparent.

I was a bit anxious about it but found an easy solution if I want to avoid it: put the camera in MF and focus with afl button. That way, the camera always focuses at full aperture.

I've had a number of Fuji x cameras, now an X-T3, and they've always focused that way, I tried with many different lenses.

From my experience, it`s not exactly like that - usually, single focus (AF-S) mode focuses with the lens wide open (no matter the aperture set, only stopping down once the focusing is done in order to measure the exposure), and continuous focus (AF-C) mode focuses with the set aperture (not wide open).

BUT, depending on the light available (and possibly some other settings, too), it is indeed possible to have the lens stopped down during focus in AF-S, too (and not necessarily to set aperture, either). I`m not sure if AF-C would focus wide open instead of at preset aperture in some case, though, but I wouldn`t be surprised, either.

Yet it is true that using manual focus (MF) mode with "instant auto-focus" (being "auto-focus lock", AF-L button by default) should always have the lens focused wide open, stopping down only for actual exposure to be made, thus a mode to use in case wide open focusing is desired (possibly especially important with wider focal lengths and stopped down apertures).