Fujifilm GF 23mm f/4 R WR Aperture Series: Pescadero Creek Side Stream (Fujifilm GFX)
See my Fujifilm GFX wish list.
This aperture series look at performance from very close range to quite a distance, with f/11 insufficient for depth of field. It gives a good idea not just of lens performance but the limitations of depth of field without techniques such as focus stacking.
Fujifilm GF 23mm f/4 Aperture Series: Pescadero Creek Side Stream
Includes images up to full resolution from f/4 - f/11.
I have no hesitation in giving my highest recommendation to the about $2600 Fujifilm GF 23mm f/4—this is the lens that anchors the system in my view.