On Tue, 28 Dec 2010 08:21 +0200, "Boris Liberman" <bori...@gmail.com> wrote: > Barry, few years ago I had Tamron 90/2.5 macro (older one) with PK-A > Adaptall adapter. It worked just fine only occasionally having electric > contact problems due to minute mechanical shift of a lens w.r.t. > adapter. I am thinking that you could find yourself another such adapter > (PK-A) on eBay or other venues that offer second hand gear and in > principle it might solve your problem. > > I did not find this little issue anything more than a minor nuisance at > the time. Sold the lens only because I wanted to buy significantly more > expensive FA 31/1.8 Limited and had no money available... >
My experience is much the same. I have a Tamron 90mm/2.5 with an adaptall KA mount. Whenever the mount stops sending info to the camera, I find just trying to turn the lens slightly clockwise/anti-clockwise re-establishes contact (it only moves fractionally). You can find these adapters on EBay but they tend to be a bit pricey these days - you may have to pay $70 to $100 for one (second hand). I'm a bit confused when you say you can't use a normal PK adaptall mount. Are you using the lens on a DSLR? - because the lens with PK mount should work in the same way as any pre-A series K mount, using the green button method in Manual mode. Before I got a KA adaptall mount I used a normal PK mount on the lens very successfully. I just tried it again and it works fine. You can get a M42 adaptall mount for the lens and use it with the Pentax M42/K adapter but I don't see how that would be a better solution than the PK adapter. Cheers Brian ++++++++++++++++++++++++++++++++++ Brian Walters Western Sydney Australia http://lyons-ryan.org/southernlight/ > > > On 12/28/2010 8:05 AM, Barry Rice wrote: > > Hey Pentaxians > > > > I do my macro work using a Tamron 90mm 1:1 F2.8 macro, which is a generic > > lens that sits on a Pentax P/KA mount. Unfortunately, the lens is starting > > to act erratically and I've figured out that it is because of the adaptall > > mount. > > > > Unfortunately, I've discovered that the Pentax adaptall mount for automatic > > lenses are no longer being made, rumour has it they were unreliable, > > although my mount lasted for about 12 years. The regular Pentax P/K mount is > > useless for this lens (I know, I have one.) > > > > I've seen references to some other kind of mount, M42 or something like > > that. Can someone 'splain to me if this is something I can use to bring my > > extremely cherished 90mm back to life? I think it is a generic mount that > > needs some kind of Pentax add-on? > > > > Cheers > > > > Barry > > > > Barry Rice, Ph.D. > > Carnivorous Plant FAQ > > sarracenia.com > > > > -- -- http://www.fastmail.fm - The way an email service should be -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
