Sharpness at 70mm

For these tests, the Olympus M.ZUIKO Digital 40-150mm f/2.8 ED Pro lens was attached to an Olympus E-M5 body, which in turn was mounted on a sturdy tripod. The self-timer was activated. The 100% crops represent about 1/400th of the total frame area.

The full frame at 70mm

Sharpness at 70mm is very high wide open, and peaks at f/5.6. The f/8 and f11 settings are also usable without serious restrictions, but once again diffraction severely impacts resolution at f16 and f22. Sharpness uniformity across the frame is excellent.

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