Sharpness at 75mm

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 75mm 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 75mm

At the centre of the image, sharpness is very good at the widest aperture available (f/2.0). It gets sharper at f/2.8 and sharper again at f/4.0. It’s sharpest between f/5.6 and f/11, getting a little softer again at f/11, before becoming softest at f/22. At the edge of the image, sharpness is very good at f/2.0 and f/2.8, but is at its best between f/4.0 and f/16, before dropping off again slightly at f/16.

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