For that sample I used a manual 7Artisans lens which has vintage characteristics. Except the Sigma 18-35 and some Tokina zooms for their versatility, I avoid modern lens designs (like the ultra sharp Panasonic/Leicas, for example). Regarding GFX 100's sharpness btw, here's a test I did yesterday comparing it to the BMPCC4k (more information on its youtube page, not via the video itself): https://www.youtube.com/watch?v=Efx6i5LMPK4&t=2s