On 4 Oct 2005 at 9:52, mike wilson wrote: > It makes the lenses lighter than if they carried a motor. It means that I > only > have one motor to carry around instead of one per lens. > > That's two appealing features for me.
>From what I've read of USM technology I'd guess that there wouldn't be much weight difference. The USM components are relatively small and due to their design, materials and level of integration may add very little to the overall weight of the lenses. Pentax AF lenses still each require drive axles and the associated gears and bearing per lens. Using a system like USM teach lens can be fitted with a matched motor. http://www.photoscene.com/sw/tour/inside.htm Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://members.ozemail.com.au/~distudio/publications/ Pentax user since 1986, PDMLer since 1998
