I have never used an autofocus system. I find myself comparing lenses with an SDM motor to ones without. For example, the 17-70 f4 has SDM but 16-45 does not. 55/1.4 does but 50/1.4 and 70/2.4 do not.
There are plenty of other differences -- notably price, weight and focal length -- and I have some idea how to balance those in relation to my usage and preferences. However, I don't have much idea how important or useful the SDM motor is, so I am asking here. Is this something that should be ignored in making a choice? An important factor? Somewhere between? -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
