On 7 Apr 2006 at 8:54, Toine wrote: > When I say doesn't autofocus. The 1.7x does nothing. My conclusion is > that the 1.7x can only autofocus when the contacts on the body are in > use (like in a A lens) or short circuited (like in a M lens). My > Tmount can't short circuit the contacts. A piece of conductive > aluminium foil does the job, now a 1.7x can autofocus with Tmounts.
History repeats, from a post of mine dated 2002: On 21 Sep 2002 at 20:02, Paul Ewins wrote: > Hi all, > is it possible to get the 1.7x AF converter to autofocus screwmount > lenses? It doesn't work "out of the box" but as there is no physical linkage > that is used for focussing it should work. Is it just a case of shorting out > one > or more of the control pins on the converter? Hi Paul, It seems so, I didn't realize this until you posted this comment as I'd never really tried it. The only difference between a screw lens + Adaptor K and a K- mount lens is the fact that the aperture/comms pins remain open circuit. Shorting to ground any of the proud pins on the AF adaptor will cause allow the AF to become active. I did creat a temporary solution by wedging some aluminium foil in the gap. The problem is that it's not easy to fix a contact in there without modifying each lens quite a bit as there is no way to add anything to the Adaptor K without adding to the film flange distance. Cheers, 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
