Sharpness at 9mm

For this test, the Panasonic Leica DG Summilux 9mm F1.7 ASPH lens was attached to a Panasonic Lumix GH6 body, which was in turn mounted to a sturdy tripod. Exposure delay mode was activated. Tonal and colour variance across the crops are due to change in natural light during the session.

The full frame at 9mm

The centre is pleasingly sharp even wide open at f/1.7, with peak performance achieved in the f/2-f/8 range. Diffraction starts to set in at f/11.

The edges aren't quite as sharp as the centre, with f/4-f/8 being the optimum settings.

Aperture	Centre Crop	Edge Crop
f/1.7
f/2
f/2.8
f/4
f/5.6
f/8
f/11
f/16