Sharpness at 18mm

For this test, the Panasonic Lumix S 18mm F1.8 lens was attached to a Panasonic Lumix S1R 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 18mm

Centre sharpness is very good wide-open at f/1.8, and outstanding from f/2.8 all the way through to f/11, with f/16 being adversely affected by diffraction.

The edges aren't quite as sharp as the centre, with f/5.6 to f/11 producing the sharpest results.

Aperture	Centre Crop	Edge Crop
f/1.8
f/2
f/2.8
f/4
f/5.6
f/8
f/11
f/16