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Lens review

Canon EF 50 mm f/1.4 USM

15 December 2009
Szymon Starczewski

7. Coma and astigmatism


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Fast 50 mm lenses usually have a lot of problems with the coma and even such reputable devices like a Zeiss Planar show a high level of this aberration. The Canon is not an exception to the rule and in its case the coma is also high. At the maximum aperture you see it clearly in the small Canon 20D’s sensor corner and in the full frame 1Ds MkIII’s corner as well. On stopping down by one stop the situation slightly improves for the APS-C corner but the full frame performance is still far from satisfactory. The old Canon could take a leaf out of the new Nikkor’s AF-S 50 mm f/1.4G book – it showed that it is possible to deal with the coma better.

Canon EF 50 mm f/1.4 USM - Coma and astigmatism

The Canon EF 1.4/50 USM , according to the promise, corrects the astigmatism well. Although it offers wide relative apertures, the average difference between the vertical and horizontal values amounts to just 4.5% which is a very good result.