Sharpness at 23mm

For this test, the Fujifilm 16-50mm f/3.5-5.6 OS II was mounted on a Fujifilm X-A3, which in turn was mounted on a sturdy tripod. Exposure delay mode was activated. Tonal and colour variances across the crops are due to changes in natural light during the session.

The full frame at 23mm

At 16mm, the centre of the frame is sharpest between f/4.0 and f/8.0. It's ever so slightly softer at f/11, and a bit more noticeably softer at f/16 and f/22, due to diffraction. As we’d expect, at the wider apertures, the corners are softer than the centre. At f/3.5 and f/4, there’s noticeable softness when looking at the image at 100%, getting sharper at f/5.6, before becoming fully sharp at f/8. If you’re looking at the image at normal printing or web sizes, the softness in the corners is not hugely obvious at any aperture.

The situation is similar across all of the different focal lengths - the widest aperture is not as sharp as the middle apertures. Sharpness across the frame is generally very good though, especially when looking at an image at normal printing or web reproduction sizes.

Aperture	centre Crop	edge Crop
f/4
f/5.6
f/8
f/11
f/16
f/22