On Thu, Feb 4, 2010 at 5:17 AM, Carlos R <[email protected]> wrote: > > > John Celio escribió: >> >> Hopefully the technician didn't shoehorn a Sigma motor in there somehow. >> ;) >> > > Sigma uses ring motors in their HSM lenses. They are better than than the > micro motors Pentax use in SDM lenses, I'm afraid. > > Carlos >
Is Pentax using Micromotors in all SDM lenses? Or just the dual-drive DA*'s and the 17-70. Note that ring-motors aren't inherently better, they're potentially faster and have full-time manual focus built-in, at a major cost in size. Micro-motors are much smaller. The only maker to use both types of motors and differentiate between them is Sony btw, with all SSM lenses being ring-type USM and all SAM lenses being micro-motor USM. Sigma does micro-motor AF and ring-type USM, but no micro-motor USM. Nikon doesn't differentiate and Canon differentiates by the presence of a DoF/focus distance scale (with the 50/1.4 USM being a special case), Tokina and Tamron just don't do USM at all. -- M. Adam Maas http://www.mawz.ca Explorations of the City Around Us. -- 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.
