Canon EF 400mm f/4 DO IS II USM Review

March 29, 2016 | Jack Baker | Rating star Rating star Rating star Rating star Half rating star

Sharpness at 400mm

The sharpness tests for this review were carried out using a real-world subject rather than a test chart. The Canon EF 400mm f/4 DO IS II USM lens was attached to a Canon EOS 5DS body, which in turn was mounted on a sturdy tripod. Self-timer mode was activated. Slight tonal changes are due to slight changes in natural light during the session.

The full frameThe full frame at 400mm

Our sharpness test shots turned out disappointingly soft at f/4 and f/5.6, despite shooting multiple frames and using every possible measure to prevent camera shake. As our real world sample images at these apertures were very sharp, we suspect the softness during sharpness testing is likely due to an autofocussing anomaly, compounded by the extremely limited depth of field at this focal length when using large apertures.

At f/8, detail really pops, and the lens maintains excellent sharpness until f/22 where diffraction softens things very slightly. At all apertures, corner sharpness is near-identical to the centre of frame.

Aperture Centre Crop Edge Crop
f/4 f4.jpg f4.jpg
f/5.6 f5_6.jpg f5_6.jpg
f/8 f8.jpg f8.jpg
f/11 f11.jpg f11.jpg
f/16 f16.jpg f16.jpg
f/22 f22.jpg f22.jpg
f/32 f32.jpg f32.jpg