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Lens review

Pentax smc FA 35 mm f/2 AL

20 July 2010
Szymon Starczewski

7. Coma and astigmatism

Looking at the coma results the Pentax competitors achieved we can notice that every instrument fared differently. The Nikkor didn’t exactly distinguish itself, showing huge coma wide open; it remained high even after stopping down by one stop. The Canon fared the other way round as it had acceptable coma at the maximum aperture, lower than that of the Nikkor after stopping down.

Pentax can be placed somewhere in between. Its coma is a bit higher than that of the Canon but significantly lower than the Nikkor’s. The fact that by f/2.8 this aberration decreases a lot is also important.

Pentax smc FA 35 mm f/2 AL - Coma and astigmatism


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The Pentax 2/35 corrects the astigmatism equally well. The average distance between vertical and horizontal MTF50 values amounted to 4.8% which is a very good result. It’s true that the Nikkor had only 3% here but the Canon fared definitely worse for a change, with the result reaching as much as 17%.