Sigma 24mm f1.8 Autofocus Test

In this test, I evaluate the performance of AF and compare it to MF. I focused manually every MF case and re-focused using AF for every AF case. You should be OK with AF when shooting above f4. At f4 or below, be safe and use MF. I have performed this test with the 28mm and 20mm on this subject and with the 28mm on two other types of subjects and the results in all cases were the same. Distance to the wall from the sensor was 12 feet. A full-frame 900/600 72DPI f8/MF sample is below. The final image is a comparison of multiple AF shots all at f1.8 where I forced the camera to re-focus each time by sticking my hand in between the camera and the image.

Full Frame F8 MF 900/600 72DPI

af f1.8 mf f1.8

af f2 mf f2

af f2.8 mf f2.8

af f4 mf f4

af f5.6 mf f5.6

af f8 mf f8

af f11 mf f11

af f16 mf f16

af f22 mf f22

Autofocus series of shots, from worst to best, all at f1.8