Sigma 50-150 mm f/2.8 APO EX DC HSM review - Coma and astigmatism

Have you rated your lenses yet?

Sigma 50-150 mm f/2.8 APO EX DC HSM

21 September 2007

Arkadiusz Olech

7. Coma and astigmatism

Coma is corrected almost perfectly. Again performance in this category is similar to Sigma 70-200 f/2.8. In both cases image of the diode is almost ideally round in the center and at the borders. Well done!

Sigma 50-150 mm f/2.8 APO EX DC HSM - Coma and astigmatism

Astigmatism correction is good only for 50 mm. No wonder image resolution at border was so excellent. For this focal length average difference between horizontal and vertical values of MTF50 function is only 3%.

Please Support Us

If you enjoy our reviews and articles, and you want us to continue our work please, support our website by donating through PayPal. The funds are going to be used for paying our editorial team, renting servers, and equipping our testing studio; only that way we will be able to continue providing you interesting content for free.

- - - - - - - - - - - - - - - - - advertisement - - - - - - - - - - - - - - - - -

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

It is much worse for longer focal lengths. We can see that beside chromatic aberrations astigmatism is the main reason of worse image resolution at borders. For 100 mm it is equal to 12% and for 150 mm goes even higher to 14%.