Lens review
2010-09-14
Sony Carl Zeiss Vario Sonnar 24-70 mm f/2.8 T* SSM
7. Coma and astigmatism
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The influence of the coma on the image quality is quite low as you can see in crops below, presenting the images of a circular diode in the centre and the corner of the frame. Noticeable deformation of the shape of the diode are seen in the middle of the focal lengths range; there, the level of this aberration is the highest but still acceptable.
When it comes to the astigmatism, its average value amounted to just 6% which is considered a low level. It should be noticed that the visibly higher results at the maximum focal length constitute a strong factor increasing the average result; it also explains partially the weaker resolution of the lens at 70 mm and by f/2.8, mentioned in the resolution chapter.
