Canon EF 85mm f/1.8 USM Interchangeable Lens Review

Canon EF 85mm f/1.8 USM Performance

This lens puts in an excellent performance as far as clarity is concerned. Sharpness in the centre is already very good at f/1.8 and approaching good levels towards the edges. Stopping down the lens improves clarity across the frame and peak quality is achieved between f/5.6 and f/8, where the sharpness in the centre is outstanding and exceeding excellent levels towards the edges.

MTF @ 85mm

How to read our charts The blue column represents readings from the centre of the picture frame at the various apertures and the green is from the edges. Averaging them out gives the red weighted column. The scale on the left side is an indication of actual image resolution. The taller the column, the better the lens performance. Simple. For this review, the lens was tested on a Canon EOS 5D Mark II using Imatest.

Chromatic aberrations are also well controlled. At their worst levels they reach half a pixel width towards the edges of the frame at f/1.8. This level is very low and shouldn't be visible, unless you really go looking for it.

Chromatic Aberration @ 85mm

How to read our charts Chromatic aberration is the lens' inability to focus on the sensor or film all colours of visible light at the same point. Severe chromatic aberration gives a noticeable fringing or a halo effect around sharp edges within the picture. It can be cured in software. Apochromatic lenses have special lens elements (aspheric, extra-low dispersion etc) to minimize the problem, hence they usually cost more. For this review, the lens was tested on a Canon EOS 5D Mark II using Imatest.

Falloff of illumination towards the corners of the frame is also very well controlled, especially for a wide aperture lens. At f/1.8 the corners are only 0.94 stops darker than the image centre and visually uniform illumination is achieved at f/3.5.

Distortion is virtually non-existent. Imatest managed to pick up 0.207% pincushion distortion, although you would be hard pressed to see it with the naked eye.

No lens hood comes supplied with this lens, which is a shame as strong light sources outside the frame can cause a marked loss of contrast. Shooting into the light, this lens holds its own admirably, only producing flare and loss of contrast in very severe circumstances.

Add your message