Sigma 30 mm f/2.8 EX DN
- compact and quite solid casing,
- excellent image quality in the frame centre,
- decent image quality on the edge of the Micro 4/3 sensor,
- low distortion,
- well-corrected coma,
- moderate vignetting,
- silent, fast and accurate autofocus,
- good price/quality ratio.
- a bit too high astigmatism,
- noticeable chromatic aberration,
- work against bright light should have been better.
Sometimes you face such a situation: a tested instrument has good or very good results in most of categories but the overall impression, a particular slip-up or too high price make me lose all the interest. The Sigma’s 30 mm f/2.8 EX DN case it is a bit reversed. You can have some reservations in practically every category but its affordable price, good image quality, handy and well-done casing make me think I would still like to own it. The similarity of performance between the Sigma 2.8/30 and the 1.4/30 is worth emphasizing here. At first glance those two instruments have just two things in common: the name of their producer and the angle of view; they differ in aperture fastness, dimensions, image distance and optical construction as well. However their performance remains surprisingly similar.
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The Sigma 1.4/30 was also good in the centre but not so on the edge of the frame. Its chromatic aberration was on the borderline between medium and high levels. What’s more we saw noticeable issues with astigmatism there. You can only regret that the Sigma optics constructors, while designing a lens slower by as much as 2 EV didn’t manage to get rid of problems of the 1.4/30 model. You can’t have anything and you should look for positive aspects – like, for example, the price of the new model, almost two times lower than that of the Sigma 1.4/30. If a lens which costs 800 PLN reaches the peak of its possibilities near the maximum relative aperture it means further reduction of the price won’t bring you much bigger effects. Let’s finish our discussion on such an optimistic note.