Lens review
2009-10-20
Sigma 120-400 mm f/4.5-5.6 APO DG OS HSM
7. Coma and astigmatism
Looking at the diode picture at the center of the frame and the corner of it, we don’t see much difference, and this means that coma is corrected in a good way.
Sigma does very well with correcting astigmatism. The average difference between horizontal and vertical MTF50 values totaled 4% in this case, which is a very good result.
