Sharpness at 90mm

For this review, the sharpness test is carried out by photographing a real-world sample, rather than a test chart. The Leica APO-Summicron-SL 90 f/2 ASPH was mounted on a Leica SL, which was in-turn mounted on a sturdy tripod. Exposure delay was activated to prevent camera-shake. Any changes in tone you might see across the crops are due to natural light changes during the shooting session.

The full frame at 90mm

Sharpness is good at the centre at f/2, and sharper again at f/2.8. Sharpness is excellent from f/4.0 through to f/11. At f/16, sharpness gets a little softer again, before becoming the softest at f/22. The overall impression of sharpness even at the widest and narrowest apertures is extremely good at normal printing and viewing sizes. The sharpest results at the edges of the frame can be seen between f/5.6 and f/16. Sharpness drops off a little at f/22.

Aperture	Centre Crop	Edge Crop
f/2
f/2.8
f/4
f/5.6
f/8
f/11
f/16
f/22