Canon EF 400mm f/5.6 USM L - Review / Lab Test Report - Analysis
Lens Reviews - Canon EOS (APS-C)
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As to be expected from a fix-focal lens the level of distortion is absolutely negligible (0.174%).


The chart above has a real-world size of about 120x80cm.


Vignetting is basically a non-issue with the lens - at least on a 1.6x DSLR. Even wide-open the vignetting doesn't exceed ~0.25 f-stops which is negligible in the field.

MTF (resolution)

In the lab the lens delivered a very uniform performance across the tested aperture range with a very good results both in the center as well as at the borders. Overall the MTF values are marginally better than the classic EF 300mm f/4 USM L with 1.4x II but quite a bit better than both the EF 300mm f/4 USM L IS with 1.4x II and the Canon EF 100-400mm f/4.5-5.6 USM L IS (@ 400mm).

Some may be surprised that all these long tele lenses don't deliver a better performance than many wide-angle lenses. Please note that there's QUITE a bit more space between the test chart with super tele lenses so the longer the focal length the higher is the amount of air diffusion (the distance to the test chart is focal-length x 1.6 x ~40).

Please note that the MTF results are not directly comparable across the different systems!

Below is a simplified summary of the formal findings. The chart shows line widths per picture height (LW/PH) which can be taken as a measure for sharpness. If you want to know more about the MTF50 figures you may check out the corresponding Imatest Explanations

Chromatic Aberrations (CAs)

Similar to most other tele fix-focal lenses chromatic aberrations (color shadows at harsh contrast transitions) are very low and nothing to worry about.


The EF 400mm f/5.6 USM L is a very good to excellent lens in all aspects and optically a somewhat superior to the current (locally tested) 400mm alternatives - at least compared to those that are affordable for mortals. So if you can live without IS and search for a very long tele lens for wildlife or sports photography you should have a deeper look at this lens.

Optical Quality:    
Mechanical Quality:
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