Roland Mabo notes at DPR that for the comment from another DPR poster who visited the Photokina Pentax booth that his Bigmas behaved weirdly on a K-5 for the AF. So, is the Sigma HSM just incompatible with the new Pentax SAFOX IX AF system? Does the SAFOX IX uses some completely new algorithms so that the old Sigma in-lens firmware (it's just software afterall) just won't work anymore?It's not
