Sharpness

Sharpness at 75mm

For these tests, the Olympus M.ZUIKO Digital 75-300mm f/4.8-6.7 ED lens was attached to an Olympus E-PL2 body, which in turn was mounted on a sturdy tripod. The self-timer was activated. The 100% crops represent about 1/300th of the total frame area.

The full frame at 75mm

Centre sharpness is very good at f/4.8, and reaches excellent levels at f/5.6. From that point onward, the effects of diffraction start to become noticeable, although f/8 is almost indistinguishable and f/11 is still very good. The smallest aperture settings of f/16 and f/22 are best avoided.

Our sample of this lens appeared to suffer from a slight decentering problem at the 75mm setting, with the left edge of the frame being essentially as sharp as the centre at all aperture settings, but the right edge – where the edge crops are from – being somewhat softer, and not sharpening up until hitting f/11.

Aperture	Centre Crop	Edge Crop
f/4.8
f/5.6
f/8
f/11
f/16
f/22