SDM Tele converters..

Does any one know of a 1.4/1.5 or 2x converter that will give full SDM function with the 50-135 DA* lens?

I have an older Tameron 2x conveter that seems to have all the connections but the lens will only operate in manual with it.

On a side, it is interesting to note that my MZ5-n has the same connections around the K-mount as my K10D - does this mean that it too could do SDM if it had firmware capable of it?

AFAIK, they need to have the power zoom contacts. The Kenko 1.5x Pz-AF Teleplus DG does and it works fine with my SDM 300mm Pentax DA*.

Thanks, my current teleconverter does have the connections, just doesn't work

I will take a look at the Kenko.

the connections you need are the Power Zoom contacts, not the normal data contacts. These are located inside the K mount on a sortof wedge thingy at the bottom right of the opening as you look into the body (I'd show you a picture, but I don't have my K10D with me).

If you look in the MZ-5, it has the wedge but the contacts are blanked off, whereas in the K10D and other SDM/Power Zoom capable cameras they are copper.

Since SDM is just a different way of doing the same thing, any camera with the contacts would be able to do SDM if it had the necessary firmware. Alas, even if Pentax wanted to there is no way to easily update the firmware in a film body, so it wouldn't be viable to do.

You say firmware in a film body, but wouldn't you need hardware to make SDM work :

I don't think so because the hardware is present. The PZ bodies all support AF screw drive, so they already have SAFOX auto-focus circuitry, albeit an earlier version. They also have power contacts to provide the juice for the motors, and all seven data transfer contacts. The only thing they lack is the ability to transmit commands from the AF system to the motors via the data transfer contacts.

There may be an issue particularly with the early Z series bodies about how the systems of the camera are hung together, it may be physically impossible to interface the AF system with the digital contacts, but this we will never know unless some mad fool dismanled a Z-50 and tried it.

/me looks accusingly at Don

These are the ones that are also on my current teleconverter. This is when I went to the MZ5n as I bought it to go with that camera.

The strange thing as even without the SDM contact, the screw drive should work. Does this mean that the lens is deciding to go manual? I have tried the lens on my MZ5n and it works fine through the screw drive. Guess my next test is my current teleconverter + lens on my MZ5n.

oops, looks like the MZ-5n does have PZ contacts after all, my bad! I was assuming that all the MZ series bar the MZ-S lacked these contacts.

My guess is the lens identifies itself to the camera and the camera goes "Aha, a DA* lens. I will use SDM" but then for some reason the pass through isn't working. Have you tried cleaning the power pass through contacts on the TC?

It almost suggest that this type of lens has been planned for some time!

I will give it a go, any suggestion on what to use? I usually use a penknife to clean contacts - ideal for battery contacts, but a lens