Now i have run out of Fujifilm GF 500mm lens images - therefore I use other ones taken with Pentax 645 FA lenses *grin*

Like the Pentax 645 FA 400/5.6 ED above - which does very well after all - when i scrutinize the people waiting for the buss - in fine details (after slight sharpening).

Well, it is all sharp.

So, i may undervalue that lens due to its vintage status, by being a bit "crude" in its AF behavior. Also because in general it works very well - yet at lower light levels (cloudy, shadow,etc) i think the AF focus is slightly more difficult to acquire. You simply have to pay more attention, keep really still and make sure the AF is correct.

See below !

Push the finger on the camera shutter
(gently) a couple of times

Fringer writes on their homepage, (about their P645-GFX AF adapter) that when you should push the shutter button gently several times (half way) the focus tends to settle more often correctly at your subject. (Which it tends not always to do, when you only push the button once half-way. Here you can occasionally get images in which the subject is ever so slightly out of focus.

I often push the shutter button several times before i take the shot !

Especially with the Fujifilm GFX 50s II camera, I did this "by default" always - just to make sure that the focus hits exactly on the spot of my desire. (Due to that i sometimes got OOF images with native Fujinon lenses (!), if i relied on just taking the shot without hesitation - like Bam ! The focus would sometimes sit somewhere else. This even happened with rather trivial motives; focusing on the horizon or buildings at infinity) - but wasn't sharp at all.

That's when i started to touch the shutter button several times - it would settle the AF more often correctly.

In that regard the GFX 50s II was more unreliable compared to the Fujifilm GFX 100s II which I am now using. Don't get me wrong, the GFX 50s II did sharp photos most of the time. It just would occasionally fail "just like that" or when i was too fast or sloppy - and result into wrong focused / blurry images.

Modern 102 MP sensor version

Well, the sensor of the GFX 100 series is a much more modern one - supporting not only contrast based AF but also the faster PDAF - which makes all the difference.

It is a joy for me to work with the Fujifilm GFX 100s II camera - i can tell you that !