Tele-convertor

My latest ebay bargain? arrived today, a Takumar - A 2X Tele-converter.

I tried it on My Samsung GX 1S with my SMC Pentax-A 50mm f1.7 and it works fine however the same lens and teleconverter fitted to my Pentax K20d won't work properly - with the lens aperture ring on the 'A' setting it stops down to f22 and the viewfinder is very dark, I can get it to work by enabling use of the aperture ring in the camera menu and setting the apertures manually but don't understand why the 'A' setting doesn't work.

Any help would be gratefully received.

Hi Haydn. My Takumar works effectively with all my lens on the K10D. Can only suggest you visit a friendly Pentax retailer and ask them to try it on a K20D. I have no experience of the K20d and none of my friends have this camera. Not much help, I'm afraid. regards Ronald.

Ronald,

Thanks for your reply, I am fairly sure that there isn't a problem with my K20 body but then again the convertor works with my Samsung