Hasselblad X1D + Hasselblad XCD 21mm f/4 Aperture Series: Contemplating Rock Creek
See my Hasselblad medium format wish list.
This series looks at performance with the Hasselblad XCD 21mm f/4 focus well off center and at close range and how the background holds up and develops sharpness, namely is there field curvature or focus shift?
Hasselblad XCD 21mm f/4 Aperture Series: Contemplating Rock Creek
Includes images up to full camera resolution from f/4 through f/12.
This is the kind of performance I can get very excited about on a large sensor. If my budget allowed, the 21m f/4 would be my #1 pick for the X1D because wide angle lenses this good are not easy to come by, particularly on medium format. My reference points are lenses such as the Zeiss Milvus 18mm f/2.8 Distagon and the Zeiss Batis 18mm f/2.8 Distagon and the Sigma 14-24mm f/2.8 DG HSM Art (all 35mm format lenses). See my Hasselblad X1D wishlist.

Hasselblad X1D + Hasselblad XCD 21mm f/4 @ 18mm equiv (21mm) ENV: Rock Creek, altitude 9950 ft / 3033 m
focus at f/4 on orange tree
[low-res image for bot]