Get Pentax 645Z at B&H Photo.
In my review of the Pentax 645Z in Medium Format is a close range still-life study with soft lighting and very pleasing bokeh:
Aperture Series: Atlas Permaguard (645Z)
This aperture series shows a peripheral forward focus shift that might be useful to understand for critical work. Includes HD and UltraHD images and large crops.
Artifacts of early Miners
Pentax 645Z + 90mm f/2.8 @ f/5.6