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Lens review

Leica Summicron-M 28 mm f/2.0 Asph

29 March 2010
Szymon Starczewski

7. Coma and astigmatism


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Coma influences significantly image quality in the frame corners because its effects are visible at the maximum aperture and on stopping down by one stop as well. The crops below show it very clearly. With a lens of such parameters, designed to work on full frame it would be difficult to eliminate such aberration, though. Other fast lenses have fared much worse here.

Leica Summicron-M 28 mm f/2.0 Asph - Coma and astigmatism

When it comes to the astigmatism its influence is also felt. The average difference between horizontal and vertical MTF50 function values amounts to 11% here. Such a result can be hardly called sensational but it is not worse than average either.