Lens review

Sigma 4.5 mm f/2.8 EX DC CIRCULAR FISHEYE HSM

5. Chromatic aberration

Next category, other problems. The graph below shows huge chromatic aberration values which might suggest an equally huge slip-up of the tested lens. You should take into account the fact that the areas where the aberration is measured in the case of a circular “fisheye” are moved away from the frame centre and positioned in a place where any aberrations and deformations make themselves felt. As a result the chromatic aberration, although really high at the very edge, in most of the field of view won’t disturb us significantly.