Originally posted by vonBaloney I just got a firmware update on the non-OS version of the Sigma 120-400 to enable CDAF autofocus (live view). PDAF (through the viewfinder) worked fine before the update though.
Your camera may need the latest firmware also.
Interesting, my K-30 has version 1.06 I think it's the latest firmware? Will ask Sigma to update the firmware of the lens and try it out again.
Btw, I just tried one of my friend's Sigma 70-200/2.8 Macro II HSM lens and it works perfectly on my K-30. Even in indoor dim light it focused pretty quickly. The F2.8 helped a lot as well I guess. So the HSM shouldn't be the problem I guess?